阅读说明：本技术 能量存储装置 (Energy storage device ) 是由 J.霍华德 M.伦达尔 于 2019-07-19 设计创作，主要内容包括：公开了用于制造能源存储装置的方法。在基底上提供堆叠。堆叠包括第一电极层、第二电极层以及在第一电极层和第二电极层之间的电解质层。该方法包括与在基底上的堆叠的第二侧相反的堆叠的第一侧中形成第一凹槽,第二凹槽和第三凹槽。第一凹槽具有第一深度和包括第二电极层的第一暴露表面的第一表面。第二凹槽具有不同于第一深度的第二深度和包括第一电极层的暴露表面的第二表面。第三凹槽具有与第一深度基本相同的第三深度和包括第二电极层的第二暴露表面的第三表面。(A method for manufacturing an energy storage device is disclosed. A stack is provided on a substrate. The stack includes a first electrode layer, a second electrode layer, and an electrolyte layer between the first electrode layer and the second electrode layer. The method includes forming a first recess, a second recess, and a third recess in a first side of the stack opposite a second side of the stack on the substrate. The first recess has a first depth and a first surface including a first exposed surface of the second electrode layer. The second recess has a second depth different from the first depth and a second surface including an exposed surface of the first electrode layer. The third recess has a third depth substantially the same as the first depth and a third surface including a second exposed surface of the second electrode layer.)

1. A method of manufacturing an energy storage device, the method comprising:

providing a stack on a surface of a substrate, the stack comprising a first electrode layer, a second electrode layer, and an electrolyte layer between the first electrode layer and the second electrode layer, the first electrode layer being closer to the surface of the substrate than the second electrode layer;

forming a first recess in a first side of the stack, the first side of the stack being opposite a second side of the stack on the surface of the substrate, the first recess having a first depth and a first surface comprising a first exposed surface of the second electrode layer;

forming a second recess in the first side of the stack, the second recess having a second depth different from the first depth and a second surface comprising an exposed surface of the first electrode layer; and

forming a third recess in the first side of the stack, the third recess having a third depth substantially the same as the first depth and a third surface comprising a second exposed surface of the second electrode layer,

wherein the second groove is located between the first groove and the third groove.

2. The method of claim 1, wherein at least one of the first groove, the second groove, or the third groove is formed without cutting the substrate.

3. The method of claim 1 or 2, wherein:

the first groove is spaced apart from and substantially parallel to the second groove; and

the second groove is spaced apart from and substantially parallel to the third groove.

4. The method of any one of claims 1 to 3, wherein at least one of the first depth of the first groove, the second depth of the second groove, or the third depth of the third groove is substantially perpendicular to the plane of the surface of the substrate.

5. The method of any of claims 1-4, wherein forming the first groove, forming the second groove, and forming the third groove use at least one laser beam directed at the first side of the substrate.

6. The method of any one of claims 1 to 5,

a first groove is formed through the second electrode layer and the electrolyte layer, and exposes a first exposed surface of the second electrode layer;

the second groove penetrates through the second electrode layer, the electrolyte layer and the first electrode layer, and exposes the surface of the first electrode layer; and

the third groove is formed through the second electrode layer and the electrolyte layer, and exposes a second exposed surface of the second electrode layer.

7. The method of claim 6, wherein,

forming a first groove without cutting the first electrode layer and without cutting the substrate;

forming a second groove without cutting the substrate; and

the third grooves are formed without cutting the first electrode layer and without cutting the substrate.

8. The method of any one of claims 1 to 7, comprising providing an electrically insulating material in at least one of:

a first groove to insulate a first exposed surface of the second electrode layer from the first electrode layer;

a second groove to insulate the exposed surface of the first electrode layer from the second electrode layer; or

And a third recess to insulate the second exposed surface of the second electrode layer from the first electrode layer.

9. The method of claim 8, comprising: after disposing the electrically insulating material in the second recess, a portion of the electrically insulating material is removed to expose a third exposed surface of the second electrode layer.

10. The method of any of claims 1 to 9, comprising:

forming a first precursor recess, a second precursor recess, and a third precursor recess in a first side of the stack; and

disposing an electrically insulating material in the first precursor recess, the second precursor recess, and the third precursor recess, wherein:

a first recess is formed through the electrically insulating material in the first precursor recess;

a second recess is formed through the electrically insulating material in the second precursor recess; and

the third recess is formed through the electrically insulating material in the third precursor recess.

11. The method of claim 10, wherein the first precursor recess, the second precursor recess, and the third precursor recess are formed to have substantially the same depth as one another.

12. The method of claim 10 or 11, wherein:

the stack comprises a further first electrode layer, a further second electrode layer and a further electrolyte layer between the further first electrode layer and the further second electrode layer, the further first electrode layer being located between the second electrode layer and the further electrolyte layer; and at least one of:

forming the first groove includes:

forming a first recess through the electrically insulating material in the first precursor recess to form a first recess having a first surface comprising a first exposed surface of the second electrode layer, and such that the first exposed surface of the further second electrode layer is insulated from the first recess by the electrically insulating material; and

widening the first recess such that the first surface further comprises a first exposed surface of the further second electrode layer;

forming the second groove includes:

forming a second recess through the electrically insulating material in the second precursor recess to form a second recess having a second surface comprising the exposed surface of the first electrode layer, and such that the exposed surface of the other first electrode layer is insulated from the second recess by the electrically insulating material; and

widening the second recess such that the second surface also comprises an exposed surface of the further first electrode layer; or

Forming the third groove includes:

forming a third recess through the electrically insulating material in the third precursor recess to form a third recess having a third surface comprising a second exposed surface of the second electrode layer, and such that the second exposed surface of the further second electrode layer is insulated from the third recess by the electrically insulating material; and

the third recess is widened such that said third surface further comprises a second exposed surface of the further second electrode layer.

13. The method of claim 12, wherein at least one of:

after widening the first groove, a first portion of the first groove is narrower than a second portion of the first groove, the first portion of the first groove being closer to the first side of the substrate than the second portion of the first groove;

after widening the second groove, a first portion of the second groove is narrower than a second portion of the second groove, the first portion of the second groove being closer to the first side of the substrate than the second portion of the second groove; and

after widening the third groove, a first portion of the third groove is narrower than a second portion of the third groove, the first portion of the third groove being closer to the first side of the substrate than the second portion of the third groove.

14. The method of claim 12 or 13, wherein:

the stack comprises a further first electrode layer, a further second electrode layer and a further electrolyte layer between the further first electrode layer and the further second electrode layer, the further first electrode layer being located between the second electrode layer and the further electrolyte layer;

the first precursor recess, the second precursor recess and the third precursor recess are all formed through the further second electrode layer, the further electrolyte, the further first electrode layer, the second electrode layer, the electrolyte layer and the first electrode layer.

15. The method of any one of claims 1 to 13,

the stack comprises a further first electrode layer, a further second electrode layer and a further electrolyte layer between the further first electrode layer and the further second electrode layer, the further first electrode layer being located between the second electrode layer and the further electrolyte layer; and at least one of:

the first surface comprises a first exposed surface of another second electrode layer;

the second surface comprises an exposed surface of the further first electrode layer; or

The third surface includes a second exposed surface of another second electrode layer.

16. The method of any one of claims 1 to 15, wherein a first distance between the first and second grooves in a direction parallel to the plane of the substrate is substantially the same as a second distance between the second and third grooves in a direction parallel to the plane of the substrate.

17. An energy storage device, comprising:

a stack on a surface of a substrate, the stack comprising:

a first electrode;

a second electrode; and

an electrolyte between the first electrode and the second electrode, the first electrode being closer to the surface of the substrate than the second electrode;

a first electrical insulator in contact with the first exposed surface of the first electrode and the first exposed surface of the electrolyte without contacting at least a portion of the first exposed surface of the second electrode; and

a second electrical insulator in contact with the second exposed surface of the second electrode and the second exposed surface of the electrolyte, but not in contact with at least a portion of the second exposed surface of the first electrode.

18. The energy storage device of claim 17, wherein the first electrical insulator is disposed on a first side of the stack and the second electrical insulator is disposed on a second side of the stack opposite the first side.

19. The energy storage device of claim 18, wherein the first side of the stack and the second side of the stack are each substantially perpendicular to a plane of the surface of the substrate.

20. The energy storage device of any of claims 17-19, wherein a thickness of the substrate in a direction perpendicular to a plane of the surface of the substrate is substantially equal to or greater than a thickness of the stack in a direction perpendicular to a plane of the surface of the substrate.

21. The energy storage device of any of claims 17-20, wherein the stack comprises:

another first electrode;

another second electrode; and

a further electrolyte between a further first electrode and a further second electrode, the further first electrode being located between the second electrode and the further electrolyte,

wherein the energy storage device comprises:

a further first electrical insulator in contact with the first exposed surface of the further first electrode and the first exposed surface of the further electrolyte without contacting at least a portion of the first exposed surface of the further second electrode; and

a further second electrical insulator in contact with a second exposed surface of the further second electrode and a second exposed surface of the further electrolyte and not in contact with at least a portion of the second exposed surface of the further first electrode.

Technical Field

The invention relates to a method of manufacturing an energy storage device, an energy storage device and an intermediate structure for manufacturing an energy storage device.

Background

Energy storage devices, such as solid state thin film batteries, may be produced by forming a stack of layers on a substrate. The stack of layers typically includes a first electrode layer, a second electrode layer, and an electrolyte layer between the first electrode layer and the second electrode layer. The combination of stack and substrate may then be cut into individual parts to form individual cells.

It is desirable to provide a method of manufacturing an energy storage device that is simpler or more efficient than known manufacturing methods.

Disclosure of Invention

According to a first aspect of the invention, there is provided a method for manufacturing an energy storage device, the method comprising:

providing a stack on a surface of a substrate, the stack comprising a first electrode layer, a second electrode layer, and an electrolyte layer between the first electrode layer and the second electrode layer, the first electrode layer being closer to the surface of the substrate than the second electrode layer;

forming a first recess in a first side of the stack, the first side of the stack being opposite a second side of the stack on the surface of the substrate, the first recess having a first depth and a first surface comprising a first exposed surface of the second electrode layer;

forming a second recess in the first side of the stack, the second recess having a second depth different from the first depth and a second surface comprising an exposed surface of the first electrode layer; and

forming a third recess in the first side of the stack, the third recess having a third depth substantially the same as the first depth and a third surface comprising a second exposed surface of the second electrode layer,

wherein the second groove is located between the first groove and the third groove.

The formation of the first, second and third recesses provides regions in which electrically insulating material may be deposited. A conductive material may then be deposited to contact the exposed surfaces of the first and second electrode layers. The stack may then be divided into a plurality of cells, for example along axes corresponding to the first, second and third grooves. The first and second electrode layers of a given cell may then be connected to an external circuit using a conductive material.

Thus, the method according to the first aspect allows a plurality of cells to be formed from the stack. The method is thus scalable and may, for example, be performed as part of an efficient continuous manufacturing process (e.g., a roll-to-roll process). Moreover, by forming the first, second and third grooves in the same side (first side) of the stack, the method may be more straightforward than other methods in which the grooves are formed from different sides of the stack. For example, the stack may be processed from a single direction rather than from multiple directions to form the first, second, and third grooves. The apparatus for forming the grooves may also be less complex than in other cases where the grooves are formed from different sides of the stack.

Forming at least one of the first groove, the second groove, or the third groove without cutting the substrate. This may improve the efficiency of the method compared to methods involving at least partially cutting the substrate during forming the recess in the stack. For example, a smaller amount of material may be removed during the formation of the first, second and third recesses. Thus, the first, second and third recesses may be formed faster, and thus more efficiently, than would otherwise be the case if a large amount of material (e.g., a portion of the substrate) were removed. Furthermore, the formation of the first, second or third grooves may be more straightforward than other methods involving cutting through the substrate. For example, there may be a difference in thickness between the substrate and the stacked layers. In some cases, the substrate may be as thick as the combined stacked layers. Controlling the depth of the grooves formed through such substrates can be difficult. However, by forming the first, second, and/or third grooves without cutting the substrate, the first, second, and third depths of the first, second, and third grooves may be more easily controlled.

In an example, the first groove is spaced apart from and substantially parallel to the second groove, which is spaced apart from and substantially parallel to the third groove. This may simplify the formation of the first, second and third grooves. For example, providing a series of substantially parallel grooves is more straightforward than providing a series of grooves at different respective angles. For example, between the formation of a first groove and a second groove, or between the formation of a second groove and a third groove, there is no need to change the angular orientation of the apparatus that removes material to form the grooves.

In an example, at least one of the first depth of the first groove, the second depth of the second groove, or the third depth of the third groove is substantially perpendicular to the plane of the surface of the substrate. By forming the first, second or third recess in this manner, the subsequent deposition of electrically insulating material within the first, second or third recess may be simplified compared to an example in which the first, second or third recess is angled with respect to the plane of the surface of the substrate. For example, such an arrangement of first, second, or third grooves may facilitate or otherwise assist movement of the electrically insulating material into the respective groove and improve contact between the electrically insulating material and an exposed surface within the respective groove (e.g., an exposed surface of the first or second electrode layer).

In an example, forming the first groove, forming the second groove, and forming the third groove uses at least one laser beam directed at the first side of the substrate. This allows the first, second and third grooves to be formed using a laser ablation process. Laser ablation can be performed quickly and relatively easily controlled so that the depth of the first, second and third grooves can be precisely controlled. Furthermore, by arranging at least one laser beam to be directed to a first side of the substrate, the laser ablation system may be simpler than in other cases where there are different laser beams directed to different sides of the substrate.

In an example, a first groove is formed through the second electrode layer and the electrolyte layer, and exposes a first exposed surface of the second electrode layer; the second groove penetrates through the second electrode layer, the electrolyte layer and the first electrode layer, and exposes the surface of the first electrode layer; the third groove is formed through the second electrode layer and the electrolyte layer, and exposes a second exposed surface of the second electrode layer. This allows multiple cells to be manufactured from the same stack. In each of these cells, the first and second electrode layers may be exposed on opposite sides of the cell during subsequent processing, thereby reducing the risk of short circuits occurring.

In an example, the first groove is formed without cutting the first electrode layer and without cutting the substrate; forming the second groove without cutting the substrate; the third groove is formed without cutting the first electrode layer and without cutting the substrate. Thus, a smaller amount of material can be removed than would otherwise be the case. This may therefore improve the efficiency of the method.

In an example, the electrically insulating material is disposed in at least one of: a first groove to insulate a first exposed surface of the second electrode layer from the first electrode layer; a second groove to insulate the exposed surface of the first electrode layer from the second electrode layer; or a third recess to insulate the second exposed surface of the second electrode layer from the first electrode layer. For example, the electrically insulating material reduces the risk of short circuits that might otherwise occur if the first and second electrode layers were in electrical contact with each other.

In an example, after disposing the electrically insulating material in the second recess, a portion of the electrically insulating material is removed to expose a third exposed surface of the second electrode layer. This allows the third exposed surface of the second electrode layer to be subsequently connected to a conductive material for connection to an external circuit. It may be more straightforward to deposit the electrically insulating material in the second recess and then remove a portion of the electrically insulating material, rather than depositing a small amount of electrically insulating material in the second recess. For example, it may be difficult to more accurately control the amount of electrically insulating material deposited in the second recess. If too little electrically insulating material is deposited, other layers of the stack than the second electrode layer (e.g. the electrolyte layer or the first electrode layer) may be exposed, which may lead to a short circuit. Conversely, if too much electrically insulating material is deposited, an insufficient amount of the second electrode layer may be exposed, which may reduce electrical contact between the second electrode layer and the electrically conductive material during subsequent processing. This may reduce the effectiveness of the energy storage device. However, by depositing the electrically insulating material in the second recess and subsequently removing a portion of the electrically insulating material, the amount of electrically insulating material remaining in the control may be more accurately controlled.

In an example, the method includes forming a first precursor recess, a second precursor recess, and a third precursor recess in a first side of a stack; and providing an electrically insulating material in the first precursor recess, the second precursor recess, and the third precursor recess. In such an example, the first recess is formed through the electrically insulating material in the first precursor recess; a second recess is formed through the electrically insulating material in the second precursor recess; and the third recess is formed through the electrically insulating material in the third precursor recess. The formation of the first, second and third precursor recesses provides flexibility for subsequent processing, for example.

In an example, the first precursor groove, the second precursor groove, and the third precursor groove are formed to have substantially the same depth as each other. This may be more straightforward than forming the first, second and third precursor grooves to different depths from one another. For example, the same process may be applied to the stack to form each of the first, second, and third precursor recesses. This may be easier to control than if different processes were applied to the stack to form each of the first, second and third precursor recesses, e.g., to form the first, second and third precursor recesses with different respective depths.

In an example, the stack comprises a further first electrode layer, a further second electrode layer and a further electrolyte layer between the further first electrode layer and the further second electrode layer, the further first electrode layer being located between the second electrode layer and the further electrolyte layer. In this way, the stack comprises a plurality of sets of sub-stacks of first electrode layer-electrolyte layer-second electrode layer. Such a stack may have a greater active material to substrate ratio than a stack comprising a single first electrode layer, electrolyte layer and second electrode layer, and may therefore exhibit an increased energy density.

In such an example, at least one of:

forming the first groove includes:

forming a first recess through the electrically insulating material in the first precursor recess to form a first recess having a first surface comprising a first exposed surface of the second electrode layer, and such that the first exposed surface of the further second electrode layer is insulated from the first recess by the electrically insulating material; and

widening the first recess such that the first surface further comprises a first exposed surface of the further second electrode layer;

forming the second groove includes:

forming a second recess through the electrically insulating material in the second precursor recess to form a second recess having a second surface comprising the exposed surface of the first electrode layer, and such that the exposed surface of the other first electrode layer is insulated from the second recess by the electrically insulating material; and

widening the second recess such that the second surface further comprises an exposed surface of the further first electrode layer; or

Forming the third groove includes:

forming a third recess through the electrically insulating material in the third precursor recess to form a third recess having a third surface comprising a second exposed surface of the second electrode layer, and such that the second exposed surface of the further second electrode layer is insulated from the third recess by the electrically insulating material; and

the third recess is widened such that said third surface further comprises a second exposed surface of the further second electrode layer.

In these examples, the formation of the first, second, or third grooves may be a multi-step process. For example, for the first recess, the first exposed surface of the second electrode layer may be exposed before the first exposed surface of the further second electrode layer is subsequently exposed. In this way, exposed surfaces of the electrode layers for a plurality of different sub-stacks may be formed. This allows a stack comprising a plurality of sub-stacks to be formed in an efficient manner. Furthermore, the exposed surfaces of the first electrode layers of different sub-stacks may be connected in parallel in a simple manner. Similarly, the exposed surfaces of the second electrode layers of different sub-stacks may also be connected in parallel. This allows for efficient manufacturing of multi-cell energy storage devices.

In an example, at least one of:

after widening the first groove, a first portion of the first groove is narrower than a second portion of the first groove, the first portion of the first groove being closer to the first side of the substrate than the second portion of the first groove;

after widening the second groove, a first portion of the second groove is narrower than a second portion of the second groove, the first portion of the second groove being closer to the first side of the substrate than the second portion of the second groove; and

after widening the third groove, a first portion of the third groove is narrower than a second portion of the third groove, the first portion of the third groove being closer to the first side of the substrate than the second portion of the third groove.

This provides, for example, a series of shelf portions within the first, second or third recesses upon which the conductive material may be deposited. This therefore facilitates the connection of the exposed surface within the first, second or third recess with the conductive material to allow the stacked electrode layers to be connected to an external circuit.

In an example, the stack comprises a further first electrode layer, a further second electrode layer and a further electrolyte layer between the further first electrode layer and the further second electrode layer, the further first electrode layer being located between the second electrode layer and the further electrolyte layer. In such an example, the first precursor recess, the second precursor recess, and the third precursor recess are each formed through another second electrode layer, another electrolyte, another first electrode layer, a second electrode layer, an electrolyte layer, and a first electrode layer. Thus, the stack may comprise two sub-stacks, so that the method may be easily extended. This may further improve the efficiency of the method for manufacturing the energy storage device. Further, the energy storage device may have a greater energy density than other energy storage devices, which have a lower active material to substrate ratio (e.g., inert materials, which do not contribute to energy storage).

In such an example, at least one of: the first surface comprises a first exposed surface of the further second electrode layer; the second surface comprises an exposed surface of the further first electrode layer; or the third surface comprises a second exposed surface of the further second electrode layer. In this way, the first surface of the first recess may comprise the exposed surfaces of the second electrode layer and the further second electrode layer, each of which may be a cathode. Similarly, the second surface of the second recess may comprise exposed surfaces of the first electrode layer and the further first electrode layer, each of which may be an anode. The first and second grooves may be separated from each other by a portion of the stack. Thus, by a part of the stack, the conductive material connected to the second and further second electrode layers (in the first recess) can be separated from the conductive material connected to the first and further first electrode layers (in the second recess). This reduces the risk of short circuits occurring, for example. In a similar manner, another portion of the stack may separate the second and third grooves, further reducing the likelihood of shorting.

In an example, a first distance between the first groove and the second groove in a direction parallel to the plane of the substrate is substantially the same as a second distance between the second groove and the third groove in a direction parallel to the plane of the substrate. With this arrangement, the method can be performed more efficiently (e.g., using a normalized, predetermined, or fixed distance between adjacent grooves) than in other cases where the distance between adjacent grooves can vary. Each of the first, second, and third grooves may correspond to a boundary between adjacent cells of the multi-cell energy storage device. In this case, a constant or regular distance between adjacent grooves facilitates the creation of a z-shaped folded structure (by folding the intermediate structure comprising the stack and the substrate back on itself), from which a single cell can be created by cutting through the intermediate structure along an axis corresponding to one of the grooves. For example, a regular distance between adjacent grooves may make it easier to align the cells with each other (e.g., in a vertical direction) during creation of the z-folded arrangement.

According to a second aspect of the present invention, there is provided an energy storage device comprising:

a stack on a surface of a substrate, the stack comprising:

a first electrode;

a second electrode; and

an electrolyte between the first electrode and the second electrode, the first electrode being closer to the surface of the substrate than the second electrode;

a first electrical insulator in contact with the first exposed surface of the first electrode and the first exposed surface of the electrolyte without contacting at least a portion of the first exposed surface of the second electrode; and

a second electrical insulator in contact with the second exposed surface of the second electrode and the second exposed surface of the electrolyte, but not in contact with at least a portion of the second exposed surface of the first electrode.

Such an energy storage device may be manufactured in an efficient manner, for example using a method according to the first aspect of the invention. The first exposed surface of the second electrode and the second exposed surface of the first electrode may be connected to an external circuit via a conductive material.

In an example, the first electrical insulator is disposed on a first side of the stack and the second electrical insulator is disposed on a second side of the stack opposite the first side. In these examples, the first exposed surface of the second electrode may be on a first side of the stack and the second exposed surface of the first electrode may be on a second side of the stack. In this way, the stack itself may separate the first exposed surface of the second electrode from the second exposed surface of the first electrode. At the first side of the stack, a first electrical insulator may insulate a first exposed surface of the first electrode (which may also be at the first side of the stack) from a first exposed surface of the second electrode. Similarly, at the second side of the stack, a second electrical insulator may insulate a second exposed surface of the second electrode (which may also be at the second side of the stack) from a second exposed surface of the first electrode. In this way, short circuits can be effectively prevented or reduced.

In an example, the first side of the stack and the second side of the stack are both substantially perpendicular to a plane of the surface of the substrate. This may simplify the formation of the stack compared to the example where the first and second sides of the stack are angled with respect to the plane of the surface of the substrate.

In an example, a thickness of the substrate in a direction perpendicular to a plane of a surface of the substrate is substantially equal to or greater than a thickness of the stack in a direction perpendicular to a plane of a surface of the substrate. In this case, the energy storage device may be directly manufactured, for example, using the method according to the first aspect of the invention. For example, the depth of the first, second and third recesses (which may then be at least partially filled with an electrically insulating material, e.g. to form first and second electrical insulators) may be more easily controlled.

In an example, the stack comprises a further first electrode, a further second electrode and a further electrolyte between the further first electrode and the further second electrode, the further first electrode being located between the second electrode and the further electrolyte. In such an example, the energy storage device comprises: a further first electrical insulator in contact with the first exposed surface of the further first electrode and the first exposed surface of the further electrolyte and not in contact with at least a portion of the first exposed surface of the further second electrode; and another second electrical insulator in contact with a second exposed surface of the other second electrode and a second exposed surface of the other electrolyte, but not in contact with at least a portion of the second exposed surface of the other first electrode. Thus, a stack in such an example may be considered to comprise a plurality of sub-stacks. For example, such a stack has a greater energy density than other stacks having only a single sub-stack. The exposed surfaces of the first electrode layers of different sub-stacks may be connected in parallel in a simple manner, for example using a conductive material. Similarly, the exposed surfaces of the second electrode layers of different sub-stacks may also be connected in parallel, e.g. using a conductive material. This allows for efficient manufacturing of multi-cell energy storage devices. The first, further first, second and further second electrical insulators, e.g. the various components of the energy storage are insulated from each other sufficiently to avoid or reduce the risk of short circuits. However, sufficient exposed surface is provided to enable the stack to be effectively connected to external circuitry.

Other features will become apparent from the following description, given by way of example only, which is made with reference to the accompanying drawings.

Drawings

FIG. 1 is a schematic illustration of a stack for an energy storage device according to an example;

FIG. 2 is a schematic illustration of an example for processing the stack of FIG. 1 to fabricate an energy storage device, according to an example;

fig. 3a to 3e are schematic diagrams illustrating a method of manufacturing an energy storage device according to an example; and

fig. 4a to 4f are schematic diagrams illustrating a method of manufacturing an energy storage according to a further example.

Detailed Description

The details of the method, structure and apparatus according to the examples will become apparent from the accompanying drawings, which are referenced, by way of example. In this specification, for purposes of explanation, numerous specific details of certain examples are set forth. Reference in the specification to "an example" or similar language means that a particular feature, structure, or characteristic described in connection with the example is included in at least one example, but not necessarily in other examples. It should also be noted that certain examples are schematically depicted, where certain features are omitted and/or have to be simplified in order to facilitate explanation and understanding of the concepts underlying the examples.

Fig. 1 shows a stack 100 of layers for an energy storage device. For example, the stack 100 of fig. 1 may be used as part of a thin film energy storage device having a solid electrolyte.

In fig. 1, a stack 100 is on a substrate 102. The substrate 102 is, for example, glass or a polymer, and may be rigid or flexible. The substrate 102 is generally planar. Although the stack 100 is shown in fig. 1 as directly contacting the substrate 102, in other examples, one or more additional layers may be present between the stack 100 and the substrate 102. Thus, unless stated otherwise, reference herein to an element being "on" another element is understood to include direct or indirect contact. In other words, one element on another element may be contacting the other element or not be in contact with the other element, but is typically supported by one or more intervening elements, yet still be on or overlapping the other element.

The stack 100 of fig. 1 includes a first electrode layer 104, an electrolyte layer 106, and a second electrode layer 108. In the example of fig. 1, the second electrode layer 108 is further from the substrate 102 than the first electrode layer 104, and the electrolyte layer 106 is located between the first electrode layer 104 and the second electrode layer 108.

The first electrode layer 104 may function as a positive current collector layer. In such an example, the first electrode layer 104 may form a positive electrode layer (i.e., may correspond to a cathode during discharge of a cell including the energy storage device of the stack 100). The first electrode layer 104 may include a material suitable for storing lithium ions through a stable chemical reaction, such as cobalt lithium oxide, lithium iron phosphate, or an alkali polysulfide salt.

In alternative examples, there may be a separate positive current collector layer, which may be located between the first electrode layer 104 and the substrate 102. In these examples, the separate positive current collector layer may comprise a nickel foil; it will be appreciated that any suitable metal may be used, for example aluminium, copper or steel, or a metallised material comprising a metallised plastic, for example aluminium on polyethylene terephthalate (PET).

The second electrode layer 108 may function as a negative current collector layer. In this case, the second electrode layer 108 may form a negative electrode layer (which may correspond to an anode during discharge of a cell including the energy storage device of the stack 100). The second electrode layer 108 may include lithium metal, graphite, silicon, or Indium Tin Oxide (ITO). For the first electrode layer 104, in other examples, the stack 100 may include a separate negative current collector layer, which may be on the second electrode layer 108, and the second electrode layer 108 is between the negative current collector layer and the substrate 102. In examples where the negative current collecting layer is a separate layer, the negative current collecting layer may include a nickel foil. However, it should be understood that any suitable metal may be used for the negative current collector layer, such as aluminum, copper or steel, or a metallized material including a metallized plastic, such as aluminum on polyethylene terephthalate (PET).

The first and second electrode layers 104, 108 are generally electrically conductive. Accordingly, since ions or electrons flow through the first electrode layer 104 and the second electrode layer 108, a current may flow through the first electrode layer 104 and the second electrode layer 108.

Electrolyte layer 106 may comprise any suitable material that is ionically conductive, but it is also an electrical insulator, such as lithium phosphorus oxynitride (LiPON). As described above, the electrolyte layer 106 is, for example, a solid layer, and may be referred to as a fast ion conductor. The solid electrolyte layer may have a structure between a liquid electrolyte, which lacks a regular structure and contains ions that can move freely, for example, and a crystalline solid. Crystalline materials have, for example, a regular structure with an ordered arrangement of atoms, which may be arranged as a two-dimensional or three-dimensional lattice. Ions of crystalline materials are generally immobile and therefore may not be able to move freely throughout the material.

For example, the stack 100 may be manufactured by depositing the first electrode layer 104 on the substrate 102. An electrolyte layer 106 is subsequently deposited on the first electrode layer 104, and then a second electrode layer 108 is deposited on the electrolyte layer 106. Each layer of the stack 100 may be deposited by overflow, which provides a simple and efficient way of producing a highly uniform layer, although other deposition methods are also possible.

The stack 100 of fig. 1 may also be processed to fabricate an energy storage device. An example of a process that may be applied to the stack 100 of fig. 1 is schematically illustrated in fig. 2.

In fig. 2, the stack 100 and the substrate 102 together form an intermediate structure 110 for manufacturing an energy storage device. In this example, the intermediate structure 110 is flexible, allowing it to be wound around a roll 112 as part of a roll-to-roll manufacturing process (sometimes referred to as an axle-to-axle manufacturing process). The intermediate structure 110 may be gradually unwound from the roll 112 and further processed.

In the example of fig. 2, a first laser 114 may be used to form a groove through intermediate structure 110 (e.g., through stack 100). The first laser 114 is arranged to apply a laser beam 116 to the intermediate structure 110 to remove portions of the intermediate structure 100, thereby forming grooves in the stack 100. This process may be referred to as laser ablation.

After forming the grooves, an electrically insulating material may be deposited in at least some of the grooves using material deposition system 118. The material deposition system 118 fills at least some of the recesses, for example, with a liquid 120 such as an organic suspending liquid material. The liquid 120 may then be solidified in the groove to form an electrically insulating plug in the groove. Electrically insulating materials may be considered non-conductive and therefore may conduct relatively small amounts of current when subjected to an electric field. Generally, an electrically insulating material (sometimes referred to as an insulator) conducts less current than a semiconducting or electrically conductive material. However, there is still a small amount of current flowing through the electrically insulating material under the influence of the electric field, since even insulators may comprise charge carriers carrying a small amount of current. In the examples herein, such a material may be considered electrically insulating, where the material is sufficiently electrically insulating to perform the function of an insulator. This function may be performed, for example, where the material sufficiently insulates one element from another element to avoid shorting.

Referring to fig. 2, after depositing the electrically insulating material, the intermediate structure 110 is cut along at least some of the grooves to form individual cells for the energy storage device. In the example shown in fig. 2, hundreds and possibly thousands of cells may be cut from a roll of intermediate structures 110, allowing multiple cells to be manufactured in an efficient manner.

In fig. 2, the cutting operation is performed using a second laser 122 arranged to apply a laser beam 124 to the intermediate structure 110. Each cut may, for example, pass through the centre of the insulating plug so that the plug is divided into two parts, each part forming a protective covering over the exposed surface to which it has been attached, including the edges. Cutting through the entire stack in this manner forms exposed surfaces of the first and second electrode layers 104, 108.

Although not shown in fig. 2 (only schematically), it should be understood that after depositing the electrically insulating material, the intermediate structure 110 may be folded back on itself to form a z-folded structure having at least ten layers, possibly hundreds, and possibly even thousands of layers, with each insulating plug aligned. The laser cutting process performed by the second laser 122 may then be used to cut the z-fold structure for each of the aligned sets of plugs in a single cutting operation.

After cutting the cell, electrical connectors may be provided along opposite sides of the cell, such that the first electrical connector on one side of the cell contacts the first electrode layer 104 (which may be considered to form the first electrode after the cell has been separated from the rest of the intermediate structure 110), but is prevented from contacting other layers by the electrically insulating material. Similarly, a second electrical connector on the opposite side of the cell may be arranged in contact with the second electrode layer 108 (which may be considered to form the second electrode after the cell has been separated from the rest of the intermediate structure 110), but is prevented from contacting other layers by the insulating material. Thus, the insulating material may reduce the risk of short circuits occurring between the first and second electrode layers 104, 108 and other layers in each cell. The first and second electrical connectors may be, for example, a metallic material applied to an edge of the stack 110 (or to an edge of the intermediate structure 110) by sputtering. Therefore, the batteries can be efficiently and easily connected in parallel.

Fig. 3 a-3 e (collectively fig. 3) are schematic diagrams illustrating features of an example method of manufacturing an energy storage device. Features of figure 3 that are identical to corresponding features of figure 1 are identified with the same reference numerals. The corresponding description should be taken. In each of fig. 3a to 3e, the same reference numerals are used to denote the same elements. However, for clarity, not all elements are labeled in each of fig. 3a through 3 e. However, since the processes of fig. 3a to 3e may be applied sequentially to the same stack, there may be elements that are labeled in one of fig. 3a to 3e but not in the other of fig. 3a to 3 e.

Prior to fig. 3a, the method according to fig. 3 comprises providing a stack 100 on a surface 126 of the substrate 102. In this example, stack 100 and surface 102 are as shown in FIG. 1. However, in other examples, the method according to fig. 3 may be applied to other stacks having different structures or layers than those shown in fig. 1.

The layers of the stack 100 (in this case, the first electrode layer 104, the electrolyte layer 106, and the second electrode layer 108) may be sequentially disposed. However, in other examples, a partially assembled substrate may be provided. For example, the stack comprising the first electrode layer, the electrolyte layer and the second electrode layer may have been arranged on the substrate before providing the substrate.

In fig. 3a, a first groove 128a, a second groove 128b and a third groove 128c are formed in a first side 130 of the stack 100. The first, second, and third grooves 128a-128c may be collectively referred to using reference numeral 128. The first side 130 of the stack 100 is opposite the second side of the stack 100, which is on the surface 126 of the substrate 102. Thus, the first side 130 of the stack 100 is, for example, an exposed surface of the stack 100 that is not in contact with or covered by another component. In this example, the first side 130 of the stack 100 is an upper surface of the stack 100, although this need not be the case in other examples.

The grooves are, for example, channels, grooves or grooves, which may be continuous or discontinuous. In some examples, the grooves may be elongated. The recess may extend partially through the layers of the stack 100, or extend through all of the layers of the stack 100 to expose a portion of the substrate 102. The grooves provide, for example, a channel for subsequent deposition of other materials such as liquids or other fluids.

In FIG. 3a, the first groove 128a has a first depth d₁The second groove 128b has a second depth d₂And the third groove 128c has a third depth d₃. A first depth d₁And a third depth d₃Substantially the same, and a first depth d₁And a second depth d₂Different. Each depth d of the groove 128 is taken in a direction substantially perpendicular to the plane of the surface 126 of the substrate 102 in FIG. 3a₁，d₂，d₃. A direction can be considered substantially perpendicular to a plane where the direction is completely perpendicular or approximately perpendicular to the plane, for example within measurement tolerances or within plus or minus 5, 10 or 20 degrees of deviation from perpendicular. In this case, the groove 128 may be considered to extend in or with this directionElongation in other way. In these cases, the groove 128 may additionally be elongated in a different direction, such as in a direction perpendicular to that direction (e.g., into or out of the page with reference to fig. 3 a). For example, a central axis of the groove extending from the mouth or opening of the groove toward the base of the groove may be in a direction substantially perpendicular to the plane of the surface 126 of the substrate 102.

However, in other examples, some or all of the grooves 128 may extend along an axis that is at a different angle than substantially perpendicular relative to the plane of the surface 126 of the substrate 102. For example, some or all of the grooves 128 may have an inner surface that is at an acute angle (e.g., an angle less than 90 degrees) relative to the plane of the surface 126 of the substrate 102. However, this may make it more difficult to subsequently deposit material within the recess 128 than in an example such as that of fig. 3a, in which the inner surface of the recess 128 is substantially perpendicular to the plane of the surface 126 of the substrate 102.

The first, second and third grooves 128a, 128b, 128c divide the various layers of the stack 100 into different sections. In fig. 3a, a first groove 128a divides the first electrode layer 108 into a first portion 108a and a second portion 108 b. The first groove 128a also separates the electrolyte layer 106 into a first portion 106a and a second portion 106 b. The second groove 128b separates the second portion 108b of the first electrode layer 108 from the third portion 108c of the first electrode layer 108. The second recess 128b also separates the second portion 106b of the electrolyte layer 106 from the third portion 106c of the electrolyte layer 106. In addition, the second groove 128b separates the second electrode layer 104 into the first portion 104a and the second portion 104 b. In fig. 3a, the third groove 128c separates the third portion 108c of the first electrode layer 108 from the fourth portion 108d of the first electrode layer 108 and separates the third portion 106c of the electrolyte layer 106 from the fourth portion 106d of the electrolyte layer 106. Unlike the second groove 128b, neither the first groove 128a nor the third groove 128c separates portions of the second electrode layer 104.

In fig. 3a, the first recess 128a has a first surface that includes a first exposed surface 132a of the second electrode layer 108. In this example, the first exposed surface 132a of the second electrode layer 108 is a surface of the first portion 108a of the second electrode layer 108. However, the first surface of the first recess 128a also includes exposed surfaces of the second portion 108b of the second electrode layer 108 and exposed surfaces of the first and second portions 106a, 106b of the electrolyte layer 106. The first surface of the first recess 128a additionally comprises an exposed surface of the first portion 104a of the first electrode layer 104, which in this example is an upper surface of the first portion 104a of the first electrode layer 104. Thus, in this example, a first recess 128a is formed through the second electrode layer 108 and the electrolyte layer 106. Thus, the exposed surfaces of the second electrode layer 108 and the electrolyte layer 106 form the sides of the first recess 128a, while the exposed surface of the first electrode layer 104 forms the base or bottom region of the first recess 128 a. The first recess 128a does not extend through the first electrode layer 104 or the substrate 102.

The exposed surface of the recess is, for example, the surface that is not covered or otherwise in contact with another layer after the recess is formed. As such, for example, after forming the recess, the exposed surface is, for example, uncovered, exposed, or otherwise revealed. The exposed surface may, for example, correspond to a wall, side, sidewall, or side of the groove. Thus, the exposed surface may be or include any surface within the recess that is not covered. For example, the exposed surface may be or include a vertical wall of a groove or a generally upwardly extending inner surface of a groove that extends in an upward direction relative to the base 102. This is the case in fig. 3a, where the first surface of the first recess 128a (e.g. the exposed surface of the first recess 128 a) comprises the sides of the first and second portions 108a, 108b of the first electrode layer 108 and the sides of the first and second portions 106a, 106b of the electrolyte layer 106. Alternatively, the exposed surface may be or include a horizontal wall of a groove or a wall or other surface of a groove that extends in a plane that is generally parallel to a horizontal plane or plane of the surface 126 of the substrate 102. For example, the exposed surface may be or include a horizontal bottom surface of the groove, which is, for example, the deepest surface of the groove, which may be closest to the substrate 102. In other examples, the recess may include one or more shelf or ledge portions that may extend in a plane that is generally parallel to the horizontal plane or the plane of the base.

The second recess 128b has a second surface that includes the exposed surface 134 of the first electrode layer 104. In this example, the exposed surface 134 of the first electrode layer 104 is a surface of the first portion 104a of the first electrode layer 104 (in this example, a surface of a side of the first portion 104a of the first electrode layer 104 that extends away from the plane of the surface 126 of the substrate 102). However, the second surface of the second recess 128b also includes exposed surfaces of the second and third portions 106b, 106c of the electrolyte layer 106 and exposed surfaces of the second and third portions 108b, 108c of the second electrode layer 108. Thus, in this example, the second groove 128b is formed through the second electrode layer 108, the electrolyte layer 106, and the first electrode layer 104, which for example form the side of the second groove 128 b. Although the surface 126 of the substrate 102 in fig. 3a corresponds to the base of the second groove 128b, the second groove 128b does not extend through the substrate 102. The second groove 128b is located between the first groove 128a and the third groove 128 c.

The third groove 128c has a third surface including the second exposed surface 132b of the second electrode layer 108. In this example, the second exposed surface 132b of the second electrode layer 108 is a surface of the third portion 108c of the second electrode layer 108. However, the third surface of the third recess 128c also includes exposed surfaces of the third portion 106c of the electrolyte layer 106 and exposed surfaces of the fourth portions 108d, 106d of the second electrode layer 108 and the electrolyte layer 106. The third surface of the third groove 128c also comprises an exposed surface of the second portion 104b of the first electrode layer 104, which for example corresponds to the base of the third groove 128 c. Thus, in this example, a third recess 128c is formed through the second electrode layer 108 and the electrolyte layer 106, which for example form the side faces of the third recess 128 c. But the third recess 128c does not extend through the first electrode layer 104 and the substrate 102.

Due to the first depth d of the first groove 128a₁And a third depth d of the third groove 128c₃A second depth d different from the second groove 128b₂The second groove 128b extends through the first electrode layer 104, while the first groove 128a and the third groove 128c are not deep enough to extend through the first electrode layer 104. This exposes the side surfaces (which may be considered as the second grooves) of the second electrode layer 108 within the first and third grooves 128a and 128cThe inner surfaces or sidewalls of one groove 128a and the third groove 128 c). The side surfaces of the first electrode layer 104 are not exposed within the first and third grooves 128a and 128 c. In contrast, the upper surface of the first electrode layer 104 forms the base of the first and third grooves 128a and 128 c. However, the side surface of the first electrode layer 104 is exposed in the second groove 128b deeper than the first and third grooves 128a and 128 c. However, in other examples, the side surfaces of the same layer may be exposed in each recess, while the side surfaces of different portions of the same layer are exposed in different recesses. However, in this case, the first groove and the third groove may have substantially the same depth as each other, but different depths from the second groove.

In fig. 3a, the first groove 128a is spaced apart from and substantially parallel to the second groove 128b, and the second groove 128b is spaced apart from and substantially parallel to the third groove 128 c. Two grooves can be considered substantially parallel to each other when they are completely parallel to each other or within manufacturing tolerances, or within less than 20 degrees, 15 degrees, 10 degrees, or 5 degrees. In other words, the first, second, and third grooves 128 extend in substantially the same direction as each other. This may simplify the formation of the first, second, and third grooves 128.

In fig. 3a, the groove 128 has a substantially constant cross-section or a uniform cross-section. The cross section of the groove is taken, for example, in a direction perpendicular to the depth of the groove and may thus correspond to the width of the groove. In fig. 3a, the recess 128 is cylindrical. However, in other examples, the grooves may have different shapes. For example, the cross-section of the groove may increase or decrease in size away from the base of the groove, or the size may be non-uniform. Some or all of the grooves 128 may have substantially the same width as one another, such as exactly the same width or the same width within manufacturing tolerances, or have a deviation of less than 20%, 15%, 10%, or 5%. It may be more straightforward to manufacture grooves 128 having the same width as one another rather than different widths. This may, for example, eliminate the need to adjust the manufacturing equipment between the formation of adjacent grooves that may otherwise be required to form grooves of different widths. The width of the groove may be taken in a direction parallel to the plane of the surface 126 of the substrate 102, which may be perpendicular to the depth of the groove. However, in other examples, one or more grooves may have a different width and/or shape than another groove.

In the example of fig. 3a, for example, a first distance D between the first and second grooves 128a, 128b in a direction parallel to the plane of the surface 126 of the substrate 102₁A second distance D between the second groove 128b and the third groove 128c in the same direction₂Are substantially the same. For example, two distances that are exactly the same, within measurement uncertainty, or within 20%, 15%, 10%, or 5% of each other may be considered substantially the same. With this arrangement, the grooves 128 can be more directly manufactured than in the other case where the grooves 128 are formed at irregular intervals. Furthermore, this may make it easier to align the grooves with each other in a z-folded arrangement.

Some or all of the grooves may be formed using laser ablation. "laser ablation" may refer to the removal of material from stack 100 using a laser-based process. The removal of material may comprise any of a number of physical processes. For example, material removal may include, but is not limited to, melting, melt ejection, vaporization (or sublimation), photon decomposition (single photon), photon decomposition (multiphoton), mechanical impact, thermomechanical impact, other impact-based processes, surface plasma processing, and removal by evaporation (ablation). Laser ablation, for example, involves irradiating the surface of one or more layers to be removed with a laser beam. This results in a portion of one or more layers being removed, for example. The amount of layer removed by laser ablation can be controlled by controlling the properties of the laser beam, such as the wavelength of the laser beam or the pulse length of a pulsed laser beam. Laser ablation generally allows the formation of grooves to be controlled in a straightforward and rapid manner. However, in other examples, alternative methods may be used to form some or all of the grooves, such as photolithography.

In examples using laser ablation, the groove 128 may be formed using at least one laser beam directed at the first side of the substrate 102, e.g., corresponding to the surface 126 of the substrate 102 on which the stack 100 is disposed. For example, at least one laser beam may be directed towards the first side 130 of the stack 100. By directing at least one laser beam towards the first side 130 of the stack 100, the at least one laser beam may thus be directed towards the first side of the substrate 102. To direct the at least one laser beam to the first side of the substrate 102, the laser arranged to generate the at least one laser beam may itself be located at the first side of the substrate 102 (e.g., facing the first side 130 of the stack 100). Alternatively, although at least one laser beam may be located at a different position, it may still be directed to the first side of the substrate 102 using suitable optics. For example, the at least one laser beam may be generated using a laser ablation system that includes a laser and an optical element, such as a mirror or other reflector, to deflect the at least one laser beam generated by the laser toward the first side of the substrate 102.

As such, the groove 128 may be formed by applying at least one laser beam from a single side of the stack 100. This may simplify the formation of the grooves 128 compared to the case where the laser beams are applied from different respective sides of the stack 100.

As can be seen in fig. 3a, the first, second, and/or third grooves 128a, 128b, 128c may be formed without cutting the substrate 102. In an example, the substrate 102 may be relatively thick compared to the stack 100. For example, the thickness of the substrate 102 in a direction perpendicular to the plane of the surface 126 of the substrate 102 is substantially the same as or greater than the thickness of the stack 100 in the same direction, where substantially the same, for example, means the thicknesses are identical, the same or substantially similar within manufacturing tolerances, for example within 20%, 15%, 10%, or 5% of each other. In this case, it may be more straightforward to control the depth of the grooves by cutting the grooves from the first side 130 of the stack 100 without cutting the substrate 102 than to cut the grooves through the substrate 102 into the stack 100.

In fig. 3a, the first groove 128a and the third groove 128c are formed without cutting the first electrode layer 108 and the substrate 102. The second groove 128b is formed without cutting the substrate 102. This, for example, improves the efficiency of formation of the groove 128, as compared to other examples in which additional material is removed, while still producing a groove 128 having a shape or size suitable for forming an energy storage device.

In fig. 3b, electrically insulating material 136 is deposited in first, second, and third recesses 128 (although in some cases, electrically insulating material may not be deposited in one or more recesses 128). The electrically insulating material 136 may be provided as a first liquid, for example, using an inkjet material deposition process, such as an inkjet printing process. This involves, for example, ejecting or otherwise advancing droplets of electrically insulating material 136 into grooves 128 from a nozzle, for example. Electrically insulating material 136 may be an ink, such as a dielectric ink. A suitable dielectric ink is DM-INI-7003, available from Dycotec Materials Ltd, of Unit 12Star West, Westmead Industrial Estate, Westlea, Swindon, SN 57 SW, UK. In general, electrically insulating material 126 may be any suitable dielectric material. The dielectric material is, for example, an electrical insulator, which can be polarized upon application of an electric field. Such dielectric materials also typically have low conductivity. Although in fig. 3b the same electrically insulating material 136 is deposited in each recess 128, it should be understood that in other examples, different electrically insulating materials may be deposited in one or more recesses 128.

Depositing an electrically insulating material 136 in the first recess 128a insulates the first exposed surface 132a of the second electrode layer 108 from the first electrode layer 104. Similarly, depositing electrically insulating material 136 in the second recess 128b insulates the exposed surface 134 of the first electrode layer 104 from the second electrode layer 108. Depositing an electrically insulating material 136 in the third recess 128c insulates the second exposed surface 132b of the second electrode layer 108 from the first electrode layer 104. In this way, the risk of a short circuit between the first electrode layer 104 and the second electrode layer 108 may be reduced.

After providing electrically insulating material 136 in second recess 128b, a portion of electrically insulating material 136 may be removed. This is schematically shown in fig. 3 c. The portion of electrically insulating material 136 may be removed using the same apparatus or system used to form groove 128, or using a different apparatus or system that still applies the same process as that used to form groove 128. For example, laser ablation may be used to remove the portion of electrically insulating material 136. However, other methods are possible. For example, different methods may be used to create recess 128 and remove a portion of electrically insulating material 136, as will be understood by the skilled person.

A third exposed surface 138 of the second electrode layer 108 is exposed by removing a portion of the electrically insulating material 136. In fig. 3c, the third exposed surface 138 of the second electrode layer 108 is a surface of the third portion 108b of the second electrode layer 108, but this is merely an example. In the example of fig. 3c, in addition to exposing the surface of the second portion 108b of the second electrode layer 108, the surface of the third portion 108c of the second electrode layer 108 is also exposed (although not necessarily so). A conductive material may then be deposited to contact the third exposed surface 138 of the second electrode layer 108 to connect the second electrode layer 108 to an external circuit.

After the deposition of the electrically insulating material 136, a cutting procedure may be applied, as shown in fig. 3 d. In fig. 3d, the intermediate structure of the stack 100 and the substrate 126 is cut along a first axis 140a aligned with the first groove 128a, a second axis 140b aligned with the second groove 128b, and a third axis 140c aligned with the third groove 128 c. These axes are collectively designated by reference numeral 140. In this example, the axes 140 are each aligned with the center of a respective groove 128, but in other cases such axes may not be aligned in this manner. As noted with reference to fig. 2, the cutting operation may be performed using a laser, but this is merely an example. By cutting the intermediate structure in this manner, the intermediate structure can be separated into individual cells.

As shown in fig. 3d, cutting the intermediate structure allows for the formation of a battery 142 for the energy storage device, as shown in fig. 3 e. In fig. 3e, four cells 142a-142e are formed, but typically a large number of cells may be formed from the stack 100. The first cell 142a includes a first portion 108a of the second electrode layer 108 (which may be considered to correspond to the second electrode), a first portion 106a of the electrolyte layer 106 (which may be considered to correspond to the electrolyte), a first portion 104a of the first electrode layer 104 (which may be considered to correspond to the first electrode), and a first portion 102a of the first substrate 102. The second, third and fourth cells 142b, 142c, 142d include similar layers as the first cell 142 a. Components of the second, third and fourth batteries 142b, 142c, 142d, which are similar to corresponding components of the first battery 142a, are denoted by the same reference numerals, but are accompanied by "b", "c" or "d", respectively, instead of "a".

In fig. 3e, the first electrical insulator is in contact with the exposed surface of a portion of the first electrode layer 104 and the exposed surface of a portion of the electrolyte layer 106, but not in contact with at least a portion of the exposed surface of a portion of the second electrode layer 108. The first electrical insulator is designated by reference numeral 144 in fig. 3e and is appended with "a", "b", "c" or "d" depending on whether it is associated with the first, second, third or fourth battery 142a-142d, respectively. The second electrical insulator is in contact with the exposed surface of a portion of the second electrode layer 108 and the exposed surface of a portion of the electrolyte layer 106, but not with at least a portion of the exposed surface of the first electrode layer 104. The second electrical insulator is designated by reference numeral 146 in fig. 3e and is appended with "a", "b", "c" or "d" depending on whether it is associated with the first, second, third or fourth battery 142a-142d, respectively.

In fig. 3e, the first and fourth batteries 142a, 142d include second electrical insulators 146a, 146d, but lack the first electrical insulator. However, the first battery 142a and the fourth battery 142d may be subjected to further processing to add a first electrical insulator, which may be similar to the first electrical insulators 144b, 144c of the second and third batteries 142b, 142 c.

The function of the first electrical insulator 144b and the second electrical insulator 146b will now be explained with reference to the second battery 142 b. In fig. 3e, the first electrical insulator 144b of the second cell 142b contacts the exposed surface of the second portion 104b of the first electrode layer 104b and the exposed surface of the second portion 106b of the electrolyte layer 106. Thus, the first electrical insulator 144b insulates the second portion 104b of the first electrode layer 104b from the second portion 108b of the second electrode layer 108 b. The second electrical insulator 146b of the second cell 142b also insulates the second portion 104b of the first electrode layer 104b from the second portion 108b of the second electrode layer 108 b. However, the second electrical insulator 146b of the second cell 142b accomplishes this by contacting the exposed surface of the second portion 106b of the electrolyte layer 106 with the exposed surface of the second portion 108b of the second electrode layer 108.

In this example, the first electrical insulator 144b is disposed on a first side of the second cell 142b, and the second electrical insulator 146b is disposed on a second side of the second cell 142b opposite the first side. The sides of the cells correspond, for example, to the sides of the stack of cells. The electrical insulator may be considered to be disposed at a side of the cell or stack, where the electrical insulator contacts at least a portion of an exposed surface of the side of the cell or stack. For example, the electrical insulator may extend along the side of the cell or stack (although not required). In an example such as fig. 3e, the first side of the cell or stack and the second side of the cell or stack may each be substantially perpendicular to the plane of the surface 126 of the substrate 102. In this case, the first or second side of the cell or stack need not be planar itself, but may have a non-planar surface. However, the first or second side may be substantially or approximately perpendicular to the plane of the surface 126 such that the center plane of the first or second side is perpendicular to the plane of the surface precisely, within manufacturing tolerances, or within 20 degrees, 15 degrees, 10 degrees, or 5 degrees. In this case, the first or second electrical insulator 144b, 146b may extend substantially away from the surface 126 of the substrate 102. For example, the first or second electrical insulator 144b, 146b may extend approximately vertically to cover a portion of the side of the stack of second cells 142 b.

With this arrangement, the exposed surface of the second portion 104b of the first electrode layer 104 of the second cell 142b remains uncovered by the second electrical insulator 146 b. The exposed surface of the second portion 108b of the second electrode layer 108 of the second cell 142b is also not covered by the first electrical insulator 144 b. In this way, the exposed portions of the first electrode layer 104 and the second electrode layer 108 are on opposite sides of the second cell 142 b. This allows the first electrode layer 104 and the second electrode layer 108 to be connected to an external circuit by disposing a conductive material on the opposite side of the second cell 142b and in contact with the exposed portions of the first electrode layer 104 and the second electrode layer 108. This therefore reduces the risk of a short circuit occurring between the first electrode layer 104 and the second electrode layer 108.

The third battery 142c of fig. 3e is a mirror image of the second battery 142 b. In this way, the second groove 128b of fig. 3c may be filled with an electrically insulating material 136, which electrically insulating material 136 forms the first electrical insulators 144b, 144c of the second and third cells 142b, 142c after being cut and separated into two parts. The third battery 142c may be connected to an external circuit similarly to the second battery 142 b.

Multiple batteries similar to battery 142 of fig. 3e may be connected in parallel to form a multi-battery energy storage device. For example, a first electrical connector may be used to connect each of the plurality of first electrode layers to each other, and a second electrical connector may be used to connect each of the plurality of second electrode layers to each other. Thus, the first electrical connector and the second electrical connector may provide contact points for terminals of the energy storage device. For example, the first electrical connector and the second electrical connector may provide contact points for a negative terminal and a positive terminal, respectively, of the energy storage device. The negative and positive terminals may be electrically connected across a load to power the load, thereby providing a multi-cell energy storage device.

Fig. 4 a-4 f (collectively fig. 4) are schematic diagrams illustrating methods of manufacturing energy storage devices according to further examples. Features of figure 4 which are similar to corresponding features of figures 3a to 3e are labelled with the same reference numerals increased by 100. The corresponding description should be taken. In each of fig. 4a to 4f, the same reference numerals are used to denote the same elements. However, for clarity, not all elements are labeled in each of fig. 4a through 4 f. However, since the processes of fig. 4a to 4f may be applied sequentially to the same stack, there may be elements that are labeled in one of fig. 4a to 4f but not in the other of fig. 4a to 4 f.

In fig. 4a, a stack 200 is provided on a substrate 202. Stack 200 includes a first electrode layer 204, an electrolyte layer 206, and a second electrode layer 208. However, stack 200 also includes another series of layers on top of second electrode layer 208. In this example, the further series of layers comprises two further electrolyte layers 206', 206 ", a further first electrode layer 204' and a further second electrode layer 208 '. A first further electrolyte layer 206 'separates a further first electrode layer 204' from a second electrode layer 208. A second further electrolyte layer 206 "separates a further second electrode layer 208 'from the first electrode layer 204'. Elements having the same reference number but with a prime 'or double prime' attached may be the same as the corresponding elements without the attachment. The corresponding description should be taken.

In fig. 4b, first, second and third precursor recesses 148a, 148b, 148c are formed in the first side of stack 200. First, second, and third precursor recesses 148a, 148b, 148c may be collectively referred to as precursor recesses 148. Similar to fig. 3, a first side of the stack 200 is, for example, opposite a second side of the stack 200, which contacts the surface 226 of the substrate 202. A precursor recess is a recess that is, for example, formed and then subjected to further processing (e.g., widening or partial filling with other elements) to form a subsequent recess. The precursor recesses can be formed using the same or similar methods as used to form recesses 128 of fig. 3. For example, laser ablation or alternative processes such as photolithography may be used to form the precursor grooves.

The precursor grooves 148 of fig. 4b are formed to have substantially the same depth as each other. This may simplify the formation of precursor grooves 148. However, in other examples, one or more precursor grooves may be formed to have a different depth than other precursor grooves. In fig. 4c, each precursor recess 148 is formed through a further second electrode layer 208', a second further electrolyte 206 ", a further first electrode layer 204', a first further electrolyte layer 206', a second electrode layer 208, an electrolyte layer 206 and a first electrode layer 204. However, in other examples, precursor recess 148 may be formed through a different layer than that. Further, in some cases, stack 200 may include different layers than stack 200 of fig. 4. For example, the first further electrolyte layer 206 'between the second electrode layer 208 and the further first electrode layer 206' may be omitted. Instead, a different layer (such as an insulating layer) may separate the second electrode layer 208 from the further first electrode layer 206'.

In examples such as fig. 4b, the cross-section of the precursor groove 148 can have a stepped shape, wherein the width of the precursor groove increases toward the mouth of the precursor groove (e.g., in a direction away from the substrate 202). This allows certain layers to be exposed or otherwise exposed, for example for subsequent connection to a conductive material, as shown in fig. 4 d. However, the shape of the precursor recess 148 of fig. 4b is merely an example. In other examples, precursor recess 148 may have a different shape and/or size. For example, similar to grooves 128 of fig. 3a, some or all of precursor grooves 148 may alternatively have a constant cross-section.

Fig. 4c shows the provision of electrically insulating material 236 in the precursor recess 148. The electrically insulating material 236 may be provided as described with reference to fig. 3 b.

After providing electrically insulating material 236, a recess 228 similar to recess 128 of fig. 3 may be provided. This is schematically illustrated in fig. 4d, which shows the formation of first recess 228a and second recess 228b (although it will be appreciated that the third recess may be formed similarly to the formation of first recess 228 a).

In fig. 4d, first recess 228a is formed through electrically insulating material 236 in first precursor recess 148 a. Second recess 228b is formed through the electrically insulating material in second precursor recess 148 b. Although not shown in fig. 4d, it is understood that the third recess may be formed through electrically insulating material 236 in third precursor recess 148c in a manner similar to the formation of first recess 228 a.

Electrically insulating material 236 may be removed to form first and second recesses 228a, 228b of fig. 4d in a similar manner as electrically insulating material 136 is removed to form first and second recesses 128a, 128b of fig. 3. For example, first recess 228a and second recess 228b may be formed by laser ablating a portion of electrically insulating material 236 or by using a different technique to remove a portion of electrically insulating material 236.

The first region R of the first precursor groove 148a may be removed by first removing₁A first portion of electrically insulating material 236 to form first recess 228 a. After removing the first portion of the electrically insulating material 236, the electrically insulating material may be separated into a first electrical insulator 244a, 244b, which is in contact with the surfaces of the first and second portions of the electrolyte layers 206a, 206b and the surfaces of the first and second portions of the first electrode layers 204a, 204 b. Thus, first electrical insulators 244a, 244b electrically insulate first and second electrode layers 204, 208 from each other.

Subsequently, the second region R of the first precursor groove 148a may be removed₂To widen the first recess 228a, by a second portion of electrically insulating material 236. Second region R₂E.g., in a direction parallel to the plane of the surface 226 of the substrate 202 than the first region R₁And (4) wide.

In the example of fig. 4d, the second region R₂Sufficiently wide to make the second region R₂The removal of the second portion of electrically insulating material 236 exposes surfaces of first and second portions 208a, 208b of second electrode layer 208 within first recess 228 a. In this way, the first surface of first recess 228a comprises a first exposed surface of second electrode layer 208, which in this case is an exposed surface of first portion 208a of second electrode layer 208.

In this way, the widening of the first recess 228a brings the second electrical insulators 246a, 246b into contact with the surfaces of the first and second portions 206a ', 206b' of the first further electrolyte layer 206, respectively, within the first recess 228 a. The second electrical insulators 246a, 246b also contact the surfaces of the first and second portions 204a ', 204b', respectively, of the other first electrode layer 204 within the first recess 228 a. The second electrical insulator 246a, 246b is also held in contact with the surface of the first and second portions 206a ", 206 b", respectively, of the second further electrolyte layer 206 "within the first recess 228 a. This electrically insulates the first and second portions 204a ', 204b ' of the further first electrode layer 204' from the first and second portions 208a, 208b of the second electrode layer 208. In this way, the surfaces of the first and second portions 204a ', 204b' of the further first electrode layer 204 (e.g. corresponding to the sides or sides of the further first electrode layer 204 facing the first recess 228 a) are insulated from the first recess 228a by the electrically insulating material 236. Similarly, surfaces of the first and second portions 208a ', 208b' of the further second electrode layer 208 (e.g. corresponding to sides or sides of the further first electrode layer 204 facing the first recess 228 a) are insulated from the first recess 228a by an electrically insulating material 236. This surface of the first portion 208a' of the further second electrode layer 208 may be referred to as a first exposed surface of the further second electrode layer 208, as it may be subsequently exposed.

In removing electrically insulating materialAfter the second portion of material 236, in a third region R of first precursor recess 148a₃Removing a third portion of electrically insulating material 236. Third region R₃E.g., in a direction parallel to the plane of the surface 226 of the substrate 202, than the first and second regions R₁，R₂And (4) wide. By removing the third portion of the electrically insulating material 236, the surfaces of the first and second portions 208a ', 208b ' of the further second electrode layer 208' are exposed within the first recess 228 a. This exposes a first exposed surface of the further second electrode layer 208, for example. This allows the further second electrode layer 208 'to be connected to an external circuit, for example by a conductive material deposited in contact with the first exposed surface of the further second electrode layer 208'.

As can be seen in fig. 4d, after widening the first recess 228a, a first portion of the first recess 228a (e.g. between the first and second portions 204a, 204b of the first electrode layer 204) is narrower than a second portion of the first recess 228a (e.g. between the first and second portions 204a ', 204b ' of the further first electrode layer 204 '). The first portion of the first recess 228a is, for example, closer to the substrate 202 than the second portion of the first recess 228 a. Thus, the cross-section of the first groove 228a may widen away from the base 202 (or toward the mouth of the first groove 228 a), for example. This may facilitate further processing of the stack 200, for example depositing other components such as conductive materials. However, the shape of the first groove 148 of fig. 4d is merely an example.

A similar process to that for the first recess 228a may be applied to the second recess 228 b. However, as shown in fig. 4d, the first portion of electrically insulating material 236 removed during the first widening of second recess 228b may be larger than the first portion of electrically insulating material 236 removed during the first widening of first recess 228 a. In this manner, exposed surfaces of the second portion 204b and the third portion 204c of the first electrode layer 204 may be formed within the second recess 228b by removing the first portion of the electrically insulating material 236. For example, the forming of the second recess 228b can include forming the second recess 228b through the electrically insulating material 236 in the second precursor recess 148b to form the second recess 228b having a second surface that includes an exposed surface of the first electrode layer 204 (e.g., an exposed surface of the second portion 204b of the first electrode layer 204). Conversely, during formation of second recess 228b, the faces or sides of second and third portions 208b, 208c of second electrode layer 208 may remain covered or otherwise insulated by electrically insulating material 236. Similarly, the faces or sides of the second and third portions 204a ', 204b ' of the further first electrode layer 204a ' may be kept insulated by the electrically insulating material 236. In this way, an exposed surface referred to as the further first electrode layer 204a ' (such as a surface of the second portion 204a ' of the further first electrode layer 204a ') may be kept insulated from the second recess 228b by the electrically insulating material 236. However, a second widening of the second recess 228b, for example by removing a second portion of the electrically insulating material 236, may expose exposed surfaces of the second and third portions 204b ', 204c ' of the further first electrode layer 204' within the second recess 228 b. As such, the second surface of the second recess 228b may include an exposed surface of the other first electrode layer 204 a'. The faces or sides of the second and third portions 208b ', 208 c' of the further second electrode layer 208 may remain covered or otherwise insulated by the electrically insulating material 236.

Third recesses may be formed through third precursor recess 228c in a similar manner as first recess 228a is formed through first precursor recess 228 a. Thus, after forming the first, second and third recesses in a stack 200, such as stack 200 of fig. 4, the first surface of the first recess 228a may comprise a first exposed surface of the further second electrode layer 208' and a first exposed surface of the second electrode layer 208. Similarly, the second surface of the second groove 228b may include an exposed surface of the other first electrode layer 204' and an exposed surface of the first electrode layer 204. The third surface of the third groove may include a second exposed surface of the other second electrode layer 208' and an exposed surface of the second electrode layer 208.

After forming the first, second and third recesses in the stack 200, the intermediate structure of the substrate 202 of the stack 200 may be cut as shown in fig. 4 e. The cutting of the intermediate structure in fig. 4e is similar to the cutting in fig. 3 d. For example, the intermediate structure may be cut along first and second axes 240a and 240b (collectively referenced by reference numeral 240) that are aligned with the first and second grooves 228a and 228b, respectively. The intermediate structure may also be cut along a third axis aligned with the third groove.

The cutting of the intermediate structure results in the three cells 242a-242c of fig. 4f, generally indicated by reference numeral 242. The batteries 242 may be connected together to form a multi-cell energy storage device similar to the connection of the batteries 142 of fig. 3 e.

The above examples are to be understood as illustrative examples. Further examples are envisaged. For example, a cell similar to cell 142 of fig. 3e may be formed using a method similar to that of fig. 4, wherein a precursor recess is formed that is at least partially filled with an electrically insulating material prior to subsequent selective ablation of the electrically insulating material.

For ease of illustration, fig. 3d and 4e show the cutting of the intermediate structure without the z-folding process. However, it should be understood that in some cases, intermediate structures similar to fig. 3d and 4e may be subjected to a z-folding process to form z-folded structures as described with reference to fig. 2, and then subsequently cut to separate the intermediate structures into cells. In this case, the electrically insulating material 136, 236 in the grooves 128, 228 may be aligned in a z-folded arrangement. The intermediate structure may then be cut along an axis aligned with the electrically insulating material 136, 236 (e.g., which corresponds to the axis 140, 240 aligned with the groove 128, 228). This may further improve the efficiency of the method by reducing the number of cutting operations compared to examples where no such z-fold arrangement is formed.

It is to be understood that any feature described in relation to any one example may be used alone, or in combination with other features described, and may also be used in combination with one or more features of any other example, or any combination of other examples. Furthermore, equivalents and modifications not described above may also be employed without departing from the scope of the accompanying claims.