阅读说明：本技术 一种电芯及其制造方法 (Battery cell and manufacturing method thereof ) 是由 宋鹏辉 倪尔福 罗来明 赵毓毅 于 2021-08-03 设计创作，主要内容包括：提供一种电芯,其具备：多个大小、形状相同的电化学构件；电芯壳体；麦拉膜；以及电芯盖板,所述电化学构件具有导热构件,该导热构件至少一部分位于所述电化学构件的内部,所述导热构件的至少一部分位于所述电化学构件的外部并与所述电芯壳体接触。(Provided is a battery cell provided with: a plurality of electrochemical components of the same size and shape; a cell shell; a Mylar film; and a cell cover plate, wherein the electrochemical component is provided with a heat conducting component, at least one part of the heat conducting component is positioned in the electrochemical component, and at least one part of the heat conducting component is positioned outside the electrochemical component and is in contact with the cell shell.)

1. A battery cell is provided with:

a plurality of electrochemical components of the same size and shape;

a cell case having a box shape with at least one side open, and configured to accommodate the plurality of electrochemical components;

a mylar film disposed between the plurality of electrochemical components and the cell casing in a manner that wraps the plurality of electrochemical components; and

a cell cover plate closing the at least one side opening of the cell casing and having a positive terminal and a negative terminal,

the electrochemical member has:

an electrochemical component main body which is substantially flat and comprises a positive electrode current collector, a negative electrode current collector, an electrolyte and an outer coating, wherein the positive electrode current collector and the negative electrode current collector both comprise metal foils;

a positive electrode tab formed of a metal foil integrated with the positive electrode current collector, a part of which is exposed to the outside of the electrochemical component main body and connected to the positive electrode terminal of the cell cover plate, and the remaining part of which is located inside the electrochemical component;

a negative electrode tab, which is arranged on the same side of the electrochemical component main body as the positive electrode tab, is formed by a metal foil integrated with the negative electrode current collector, one part of the negative electrode tab is exposed outside the electrochemical component main body and is connected with the negative electrode terminal of the battery core cover plate, and the rest part of the negative electrode tab is positioned inside the electrochemical component;

an outer coating layer made of an insulating material and covering the electrochemical member main body; and

at least one heat conducting member for heating or dissipating heat from the electrochemical member,

at least a portion of the thermally conductive member is located inside the electrochemical component, and at least a portion of the thermally conductive member is located outside the electrochemical component and in contact with the cell casing.

2. The cell of claim 1,

the electrochemical component is a winding core made by a winding process or a lamination made by a stacking process,

in the positive electrode current collector and the negative electrode current collector, a positive electrode material, a negative electrode material, and a separator are further stacked on a metal foil.

3. The cell of claim 1,

the heat conductive member is integrally formed with the positive electrode current collector or the negative electrode current collector, from the same material as the positive electrode current collector or the negative electrode current collector.

4. The cell of claim 1 or 2,

the heat conductive member has a portion located outside the electrochemical member and is welded to fix a plurality of the heat conductive members dispersed.

5. The cell of claim 2,

when the electrochemical component is a winding core, the heat conducting component is arranged on the electrochemical component on the same side or opposite side of the positive electrode lug and the negative electrode lug.

When the electrochemical member is a laminate, the heat conductive member is disposed at any position on the electrochemical member, and the number and direction of the heat conductive members are not limited.

6. The electrical core of any one of claims 1 to 3,

the heat conductive member is previously formed by at least one of the metal foil of the positive electrode current collector and the metal foil of the negative electrode current collector at a die cutting stage,

in the case where the heat conductive member is formed of the metal foil of the negative current collector among the metal foils of the positive current collector and the negative current collector, an insulating material is provided on a side of the heat conductive member that contacts the cell case,

in the case where the heat conductive members are formed of two of the metal foil of the positive electrode current collector and the metal foil of the negative electrode current collector, respectively, a space is provided between the two heat conductive members, or an insulating material is provided between the two heat conductive members.

7. The cell of claim 1,

the heat conductive member is formed of a sheet-like heat conductive material,

the sheet-like thermally conductive material is inserted inside the electrochemical component in the winding process of the winding core or in the stacking process of the lamination sheets.

8. The cell of claim 6,

when the electrochemical component is a winding core, the heat conducting component is arranged on the electrochemical component on the same side or opposite side of the positive electrode lug and the negative electrode lug.

When the electrochemical member is a laminate, the heat conductive member is disposed at any position on the electrochemical member, and the number and direction of the heat conductive members are not limited.

9. The cell of claim 1,

when the electrochemical member is a winding core manufactured by a winding process, a winding pin in the winding process of the winding core also serves as the heat conductive member.

10. A method of manufacturing a cell for manufacturing the cell according to any of claims 1 to 8,

the battery cell is provided with:

a plurality of electrochemical components of the same size and shape;

a cell case having a box shape with at least one side open, and configured to accommodate the plurality of electrochemical components;

a mylar film disposed between the plurality of electrochemical components and the cell casing in a manner that wraps the plurality of electrochemical components; and

a cell cover plate closing at least one side opening of the cell casing and having a positive terminal and a negative terminal,

the electrochemical member has:

an electrochemical component main body which is substantially flat and comprises a positive electrode current collector, a negative electrode current collector, an electrolyte and an outer coating, wherein the positive electrode current collector and the negative electrode current collector both comprise metal foils;

a positive electrode tab formed of a metal foil integrated with the positive electrode current collector, a part of which is exposed to the outside of the electrochemical component main body and connected to the positive electrode terminal of the cell cover plate, and the remaining part of which is located inside the electrochemical component;

a negative electrode tab, which is arranged on the same side of the electrochemical component main body as the positive electrode tab, is formed by a metal foil integrated with the negative electrode current collector, one part of the negative electrode tab is exposed outside the electrochemical component main body and is connected with the negative electrode terminal of the battery core cover plate, and the rest part of the negative electrode tab is positioned inside the electrochemical component;

an outer coating layer made of an insulating material and covering the electrochemical member main body; and

at least one heat conducting member for heating or dissipating heat from the electrochemical member,

at least a portion of the thermally conductive member is located inside the electrochemical member, and at least a portion of the thermally conductive member is located outside the electrochemical member and in contact with the cell casing;

the manufacturing method of the battery cell comprises the following steps:

pre-forming a heat conductive member at a die cutting stage using at least one of the metal foil of the positive electrode current collector and the metal foil of the negative electrode current collector;

forming the electrochemical member main body, the cathode tab, the anode tab, and the heat conductive member of the electrochemical member using a winding process or using a stacking process, thereby forming an electrochemical member;

wrapping a plurality of electrochemical components with mylar film, thereby forming a joined configuration of the plurality of electrochemical components;

after passing at least a portion of the thermally conductive member through the mylar film, encasing a plurality of bonded configurations of the electrochemical components in the cell casing; and

and using the battery cell cover plate to cover one side of the opening of the battery cell shell.

11. A method of manufacturing a cell for use in manufacturing a cell according to claim 9,

the battery cell is provided with:

at least one electrochemical component of the same size and shape, the electrochemical component having a body portion;

a positive electrode tab which is composed of a positive electrode current collector and at least one part of which is exposed out of the main body part of the electrochemical component;

a negative electrode tab which is composed of a negative electrode current collector and at least one part of which is exposed out of the main body part of the electrochemical component;

a cell housing configured in a box shape with at least one side open for accommodating at least one of the electrochemical components;

a mylar film disposed between at least one of the electrochemical components and the cell casing in a manner that encapsulates the at least one electrochemical component;

the battery cell cover plate seals at least one side opening of the battery cell shell and is provided with a positive terminal and a negative terminal which are respectively connected with the positive electrode lug and the negative electrode lug; and

at least one winding pin as a heat conducting member for heating or dissipating heat from the battery cell, wherein at least a portion of the heat conducting member is located inside the electrochemical member, and at least a portion of the heat conducting member is located outside the electrochemical member and in contact with the cell casing;

the manufacturing method of the battery cell comprises the following steps:

forming the main body portion, the positive electrode tab, and the negative electrode tab of the electrochemical member using a winding process on a winding needle basis to form an electrochemical structure;

wrapping a plurality of electrochemical components with mylar film, thereby forming a joined configuration of the plurality of electrochemical components;

after a winding pin of the winding pin passes through the mylar film, a plurality of joint structures of the electrochemical components are installed in the cell shell; and

and using the battery cell cover plate to cover one side of the opening of the battery cell shell.

12. An electrochemical component, comprising:

an electrochemical component main body which is approximately flat and comprises a positive current collector, a negative current collector, electrolyte and an outer coating, wherein the positive current collector and the negative current collector are both formed by metal foils;

a positive electrode tab formed of a metal foil integrated with the positive electrode current collector, a part of which is exposed to the outside of the electrochemical component main body and the remaining part of which is located inside the electrochemical component;

a negative electrode tab formed of a metal foil integrated with the negative electrode current collector, a part of which is exposed to the outside of the electrochemical member main body and the remaining part of which is located inside the electrochemical member;

an outer coating layer made of an insulating material and covering the electrochemical member main body; and

at least one heat conducting member for heating or dissipating heat from the electrochemical member, at least a portion of the heat conducting member being located inside the electrochemical member, at least a portion of the heat conducting member being located outside the electrochemical member.

Technical Field

The invention relates to a battery cell and a manufacturing method thereof, in particular to a heat dissipation and heating structure of the battery cell.

Background

Lithium ion batteries are the most feasible technical route in the development of energy storage products at present. The lithium ion battery has the advantages of high energy density, small self-discharge, no memory effect, wide working temperature range, quick charge and discharge, long service life, no environmental pollution and the like, and is called as a green battery.

However, lithium ion batteries exist in an operating temperature range. In the case of low ambient temperatures, the lithium ion battery needs to be heated to reach the operating temperature quickly. On the other hand, when the lithium ion battery is charged and discharged, the battery and parts on the passage generate a large amount of heat, if the heat cannot be dissipated in time, the internal temperature of the battery can be continuously increased, and the charging and discharging times and performance of the lithium ion battery can be seriously reduced after the temperature exceeds a threshold value, so that the service life of the lithium ion battery is influenced.

At present, the heating and heat dissipation methods for lithium ion batteries are mainly based on battery module or battery core grades, such as PTC heaters, heating films, heating plates, direct heating by refrigerant, and other heating methods, and natural cooling, liquid cooling, air cooling, phase change cooling, and other heat dissipation methods.

For example, patent document 1 discloses a heat dissipation structure of a battery, which includes a battery main body, a mounting frame, and a phase change energy storage plate, wherein a heat dissipation groove is formed in a bottom end surface of the mounting frame, the phase change energy storage plate is fixedly mounted inside the heat dissipation groove, and a heat dissipation fin is arranged on the mounting frame corresponding to the phase change energy storage plate, and a distal end of the heat dissipation fin extends beyond the mounting frame.

Further, patent document 2 discloses a heat dissipation structure for a soft pack lithium ion battery or a square lithium ion battery, in which a heat dissipation plate is provided between cells, and the heat dissipation plate protrudes to the outside of the battery.

However, both of the comparison documents 1 and 2 are based on heating or heat dissipation at the battery pack or cell level, and have a problem of low heating or heat dissipation efficiency. For example, in heat dissipation of the battery, heat is first conducted from the inside of the battery to the case, and then conducted from the case to the outside. Further, the battery does not always have good contact with the case, and the thermal resistance is increased, so that the temperature inside the cell is likely to be excessively high. In particular, the interlayer thermal resistance is large due to the multilayer anisotropy inside the battery, resulting in low heat dissipation efficiency.

As described in patent documents 1 and 2, various proposals have been made in the prior art for dissipating heat transferred to the case after the heat is conducted from the inside of the battery pack or the battery cell to the case. However, when the efficiency of heat transfer from the inside of the battery pack or the battery cell to the casing (in the case of heating, from the casing to the inside of the battery pack or the battery cell) is low, the conventional technology cannot further improve the heat radiation or heating efficiency. With the development of battery technology, high-rate charging has become widespread, and the amount of heat generated during charging and discharging has increased significantly compared to the past, and heat dissipation management has become a problem.

Documents of the prior art

Patent document

Patent document 1: CN212113801U

Patent document 2: CN211088452U

Disclosure of Invention

The invention provides a battery cell, a battery module and a manufacturing method of the battery cell, which are used for solving the problem that the heat dissipation and heating efficiency of the battery cell in the prior art is not high.

In order to achieve the above object, the present invention provides a battery cell including:

a plurality of electrochemical components of the same size and shape;

a cell case having a box shape with at least one side open, and configured to accommodate the plurality of electrochemical components;

a mylar film disposed between the plurality of electrochemical components and the cell casing in a manner that wraps the plurality of electrochemical components; and

a cell cover plate closing at least one side opening of the cell casing and having a positive terminal and a negative terminal,

the electrochemical member has:

an electrochemical component main body which is substantially flat and comprises a positive electrode current collector, a negative electrode current collector, an electrolyte and an outer coating, wherein the positive electrode current collector and the negative electrode current collector both comprise metal foils;

a positive electrode tab formed of a metal foil integrated with the positive electrode current collector, a part of which is exposed to the outside of the electrochemical component main body and connected to the positive electrode terminal of the cell cover plate, and the remaining part of which is located inside the electrochemical component;

a negative electrode tab, which is arranged on the same side of the electrochemical component main body as the positive electrode tab, is formed by a metal foil integrated with the negative electrode current collector, one part of the negative electrode tab is exposed outside the electrochemical component main body and is connected with the negative electrode terminal of the battery core cover plate, and the rest part of the negative electrode tab is positioned inside the electrochemical component;

an outer coating layer made of an insulating material and covering the electrochemical member main body; and

at least one heat conducting member for heating or dissipating heat from the electrochemical member,

at least a portion of the thermally conductive member is located inside the electrochemical component, and at least a portion of the thermally conductive member is located outside the electrochemical component and in contact with the cell casing.

Preferably, the electrochemical device is a winding core formed by a winding process or a laminate formed by a stacking process, and the positive electrode collector and the negative electrode collector further include a positive electrode material, a negative electrode material, and a separator laminated on a metal foil.

Further, it is preferable that the heat conductive member is formed integrally with the positive electrode current collector or the negative electrode current collector from the same material as the positive electrode current collector or the negative electrode current collector.

Further, it is preferable that a portion of the heat conductive member located outside the electrochemical member is joined by welding.

In addition, when the electrochemical element is a jelly roll, the heat conductive member is preferably provided on the electrochemical element on the same side or opposite side of the positive electrode tab and the negative electrode tab.

When the electrochemical member is a laminate, the heat conductive member is disposed at any position on the electrochemical member, and the number and direction of the heat conductive members are not limited.

Further, preferably, the heat conductive member is formed in advance in a die cutting stage from at least one of the metal foil of the positive electrode current collector and the metal foil of the negative electrode current collector,

in the case where the heat conductive member is formed of the metal foil of the negative current collector among the metal foils of the positive current collector and the negative current collector, an insulating material is provided on a side of the heat conductive member that contacts the cell case,

in the case where the heat conductive members are formed of two of the metal foil of the positive electrode current collector and the metal foil of the negative electrode current collector, respectively, a space is provided between the two heat conductive members, or an insulating material is provided between the two heat conductive members.

Further, it is preferable that the heat conductive member is formed of a sheet-like heat conductive material, and the sheet-like heat conductive material is inserted into the electrochemical member in the winding process of the winding core or the stacking process of the lamination sheets.

In addition, when the electrochemical element is a jelly roll, the heat conductive member is preferably provided on the electrochemical element on the same side or opposite side of the positive electrode tab and the negative electrode tab.

When the electrochemical member is a laminate, the heat conductive member is disposed at any position on the electrochemical member, and the number and direction of the heat conductive members are not limited.

Further, when the electrochemical element is a winding core formed by a winding process, it is preferable that a winding pin in the winding process of the winding core also serves as the heat conductive element.

In another aspect, the present invention is a method for manufacturing a battery cell, comprising the steps of,

the battery cell is provided with:

a plurality of electrochemical components of the same size and shape;

a cell case having a box shape with at least one side open, and configured to accommodate the plurality of electrochemical components;

a mylar film disposed between the plurality of electrochemical components and the cell casing in a manner that wraps the plurality of electrochemical components; and

a cell cover plate closing at least one side opening of the cell casing and having a positive terminal and a negative terminal,

the electrochemical member has:

an electrochemical component main body which is substantially flat and comprises a positive electrode current collector, a negative electrode current collector, an electrolyte and an outer coating, wherein the positive electrode current collector and the negative electrode current collector both comprise metal foils;

a positive electrode tab formed of a metal foil integrated with the positive electrode current collector, a part of which is exposed to the outside of the electrochemical component main body and connected to the positive electrode terminal of the cell cover plate, and the remaining part of which is located inside the electrochemical component;

a negative electrode tab, which is arranged on the same side of the electrochemical component main body as the positive electrode tab, is formed by a metal foil integrated with the negative electrode current collector, one part of the negative electrode tab is exposed outside the electrochemical component main body and is connected with the negative electrode terminal of the battery core cover plate, and the rest part of the negative electrode tab is positioned inside the electrochemical component;

an outer coating layer made of an insulating material and covering the electrochemical member main body; and

at least one heat conducting member for heating or dissipating heat from the electrochemical member,

at least a portion of the thermally conductive member is located inside the electrochemical member, and at least a portion of the thermally conductive member is located outside the electrochemical member and in contact with the cell casing;

the manufacturing method of the battery cell comprises the following steps:

pre-forming a heat conductive member at a die cutting stage using at least one of the metal foil of the positive electrode current collector and the metal foil of the negative electrode current collector;

forming the electrochemical member main body, the cathode tab, the anode tab, and the heat conductive member of the electrochemical member using a winding process or using a stacking process, thereby forming an electrochemical member;

wrapping a plurality of electrochemical components with mylar film, thereby forming a joined configuration of the plurality of electrochemical components;

after passing at least a portion of the thermally conductive member through the mylar film, encasing a plurality of bonded configurations of the electrochemical components in the cell casing; and

and using the battery cell cover plate to cover one side of the opening of the battery cell shell.

In another aspect of the present invention, there is provided a method for manufacturing a battery cell, comprising the steps of,

the battery cell is provided with:

at least one electrochemical component of the same size and shape, the electrochemical component having a body portion;

a positive electrode tab which is composed of a positive electrode current collector and at least one part of which is exposed out of the main body part of the electrochemical component;

a negative electrode tab which is composed of a negative electrode current collector and at least one part of which is exposed out of the main body part of the electrochemical component;

a cell housing configured in a box shape with at least one side open for accommodating at least one of the electrochemical components;

a mylar film disposed between at least one of the electrochemical components and the cell casing in a manner that encapsulates the at least one electrochemical component;

the battery cell cover plate seals at least one side opening of the battery cell shell and is provided with a positive terminal and a negative terminal which are respectively connected with the positive electrode lug and the negative electrode lug; and

at least one winding pin as a heat conducting member for heating or dissipating heat from the battery cell, wherein at least a portion of the heat conducting member is located inside the electrochemical member, and at least a portion of the heat conducting member is located outside the electrochemical member and in contact with the cell casing;

the manufacturing method of the battery cell comprises the following steps:

forming the main body portion, the positive electrode tab, and the negative electrode tab of the electrochemical member using a winding process on a winding needle basis to form an electrochemical structure;

wrapping a plurality of electrochemical components with mylar film, thereby forming a joined configuration of the plurality of electrochemical components;

after a winding pin of the winding pin passes through the mylar film, a plurality of joint structures of the electrochemical components are installed in the cell shell; and

and using the battery cell cover plate to cover one side of the opening of the battery cell shell.

In another aspect of the present invention, there is provided an electrochemical device comprising:

an electrochemical component main body which is approximately flat and comprises a positive current collector, a negative current collector, electrolyte and an outer coating, wherein the positive current collector and the negative current collector are both formed by metal foils;

a positive electrode tab formed of a metal foil integrated with the positive electrode current collector, a part of which is exposed to the outside of the electrochemical component main body and the remaining part of which is located inside the electrochemical component;

a negative electrode tab formed of a metal foil integrated with the negative electrode current collector, a part of which is exposed to the outside of the electrochemical member main body and the remaining part of which is located inside the electrochemical member;

an outer coating layer made of an insulating material and covering the electrochemical member main body; and

at least one heat conducting member for heating or dissipating heat from the electrochemical member, at least a portion of the heat conducting member being located inside the electrochemical member, at least a portion of the heat conducting member being located outside the electrochemical member.

The technical effects are as follows:

the heat conducting component arranged in the electrochemical component in the battery cell can efficiently conduct the heat of the battery cell, particularly the heat in the battery cell to the outside, and can rapidly realize the heating and heat dissipation of the battery cell.

In addition, the heat conducting component is formed in advance in the die cutting stage through at least one of the metal foil of the positive current collector and the metal foil of the negative current collector, so that the process of remanufacturing the heat conducting component by using other materials can be omitted, the light weight of the battery cell is realized, and the energy density is improved.

The heat conduction component formed by the heat conduction materials inserted into the sheet is inserted into the electric core made inside the electrochemical component, the process is simple, the heat of the electric core, particularly the heat inside the electric core, can be efficiently conducted to the outside, and the heating and the heat dissipation of the electric core can be rapidly realized.

Utilize the book needle as heat conduction component, economize the process and also economize the material, convenient good execution moreover just can be with the heat of electric core, especially the inside heat high efficiency conduction of electric core to the outside through simple structure setting, can realize the heating and the heat dissipation of electric core fast.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required to be used in the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings without creative efforts.

Fig. 1 is an exploded perspective view of a cell of the present invention.

Fig. 2 is a perspective view and a side view of the heat conductive member according to embodiment 1.

Fig. 3 is a graph comparing the heat dissipation effect of the present invention with that of the prior art through CAE simulation.

Fig. 4 is a modification of the heat conductive member according to embodiment 1.

Fig. 5 is a further modification of the heat conductive member according to embodiment 1.

Fig. 6 is a further modification of the heat conductive member according to embodiment 1.

Description of the reference numerals

1 electric core

11. 11' electrochemical component

12 electric core shell

13 mylar film

14 cell cover plate

111. 111' electrochemical component body

112 positive pole ear

113 negative pole ear

114. 114-1, 114-2, 114-3 heat conducting member

115 winding needle

115A winding needle body

115B coil stitch

It should be understood that the dimensions of the various elements shown in the figures are not drawn to scale. Further, the same or similar reference numerals denote the same or similar components.

Detailed Description

Various exemplary embodiments of the present disclosure will now be described in detail with reference to the accompanying drawings. The description of the exemplary embodiments is merely illustrative and is in no way intended to limit the disclosure, its application, or uses. The present disclosure may be embodied in many different forms and is not limited to the embodiments described herein. These embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art. It should be noted that: unless otherwise indicated, the relative arrangement of parts and steps, the composition of materials, numerical expressions and values, etc., set forth in these embodiments should be construed as merely illustrative, and not a limitation.

The use of the word "comprising" or "comprises" and the like in this disclosure is intended to mean that the elements listed before the word encompass the elements listed after the word and does not exclude the possibility that other elements may also be encompassed. "upper", "lower", "left", "right", "lateral", "longitudinal", and the like are used merely to indicate relative positional relationships, and when the absolute position of the object being described is changed, the relative positional relationships may also be changed accordingly.

All terms (including technical or scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs unless specifically defined otherwise. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

Techniques, methods, and apparatus known to those of ordinary skill in the relevant art may not be discussed in detail but are intended to be part of the specification where appropriate.

First, the basic concept of the cell is explained. The battery cells are basic units constituting a battery module, and one battery module generally includes a plurality of battery cells. The cell contains internally at least one electrochemical component, which may be a winding core formed by a winding process or a laminate formed by a stacking process. The cell referred to in the present embodiment is a lithium ion cell having an electrochemical component as a basic unit. A lithium ion battery is a secondary battery (rechargeable battery) that mainly operates by movement of lithium ions between a positive electrode and a negative electrode. During charging and discharging, Li + is inserted and extracted back and forth between two electrodes: during charging, Li + is extracted from the positive electrode and is inserted into the negative electrode through the electrolyte, and the negative electrode is in a lithium-rich state; the opposite is true during discharge.

Embodiment mode 1

Embodiment 1 is described below in detail with reference to the drawings.

Fig. 1 is an exploded perspective view of a battery cell according to the present embodiment. As shown in fig. 1, a battery cell 1 of the present invention includes: a plurality of electrochemical components 11, a cell casing 12, a mylar film 13, and a cell cover 14. In fig. 1, illustration of the tab, the heat conducting structure, and the like is omitted.

As described above, in the present embodiment, the plurality of electrochemical components 11 are cores or laminated sheets configured in a flat shape. Although not shown, the winding core is formed by stacking and winding a negative electrode metal foil, a separator, a positive electrode metal foil, and a separator, and the stack is formed by stacking a plurality of sheets each including a negative electrode metal foil, a separator, a positive electrode metal foil, and a separator. Aluminum is used as an example of the negative electrode metal foil, and nickel is used as an example of the positive electrode metal foil. The negative metal foil forms a negative current collector, and the positive metal foil forms a positive current collector. The charge and discharge of the battery cell 1 are realized by the ion movement between the positive electrode and the negative electrode. In general, the positive electrode metal foil is at zero potential (grounded).

When the electrochemical member 11 is a winding core, the electrochemical member 11 has a flat, substantially rectangular parallelepiped shape, and has substantially flat upper and lower surfaces and a plurality of side surfaces (4 side surfaces in the present embodiment) between the upper and lower surfaces. In practice, two of the four side surfaces of the winding core are slightly rounded because the winding core is manufactured by a winding process. When the thickness direction of the electrochemical member 11 is defined as the Z-axis direction, the plurality of electrochemical members 11 are arranged inside the cell casing 12 so as to overlap in the Z-axis direction.

On the other hand, when the electrochemical device 11 is a laminate, a plurality of sheets including the negative electrode metal foil, the separator, the positive electrode metal foil, and the separator may be stacked and then bundled in advance to form a laminate. In this case, the electrochemical member 11 refers to a laminated sheet. The laminated core is configured into a flat, substantially rectangular parallelepiped shape, similarly to the winding core described above, and has substantially flat upper and lower surfaces and a plurality of side surfaces (4 side surfaces in the present embodiment) between the upper and lower surfaces. However, unlike the winding process, in the case of the lamination, since the stacking process is employed, four sides are all substantially flat. Similarly to the case of the winding core, when the thickness direction of the electrochemical component 11 is defined as the Z-axis direction, the plurality of electrochemical components 11 (stacked sheets) are arranged inside the cell case 12 so as to be stacked in the Z-axis direction.

Further, a plurality of sheets including the negative electrode metal foil, the separator, the positive electrode metal foil, and the separator may not be stacked, and then bundled in advance to be a stacked sheet. In this case, the electrochemical device 11 is a stack of a plurality of sheets including a negative electrode metal foil, a separator, a positive electrode metal foil, and a separator.

The number of electrochemical components 11 may be designed according to actual circumstances, and in the present embodiment, for convenience of illustration, the example in which the battery cell 1 includes 2 electrochemical components 11 will be described. However, the number of the electrochemical devices 11 is not limited to 2, and may be more than 2.

The cell casing 12 is formed in a substantially box shape having at least one side opened, and in a typical example, the cell casing 12 is formed in a rectangular parallelepiped shape. The length and width dimensions of the cell casing 12 match those of the electrochemical components 11, and the thickness dimension of the cell casing 12 (i.e., the aforementioned dimension in the Z-axis direction) matches the sum of the thickness dimensions of the plurality of electrochemical components 11 to be housed (i.e., the aforementioned dimension in the Z-axis direction) and the thickness dimension of the heat conductive member 15 described later. At least one side of the cell casing 12 is open for mounting a cell cover 14. Thus, the cell casing 12 has substantially flat upper and lower faces, and 3 side faces between the upper and lower faces. In the present embodiment, only one side of the cell casing 12 is open, that is, the positive electrode terminal and the negative electrode terminal, which will be described later, are exposed on the same side. However, the cell case 12 may have openings on both sides or more, and a positive electrode terminal and a negative electrode terminal, which will be described later, may be exposed on different sides, or openings for other purposes may be provided. In a typical example, the cell casing 12 is an aluminum casing. It should be noted that, in a typical example, the positive electrode metal foil is at zero potential, and therefore insulation is not generally required between the positive electrode metal foil and the cell casing 12, but insulation is required between the negative electrode metal foil and the cell casing 12.

The mylar film 13 is a polyester film for realizing insulation, corrosion prevention, and the like of the electrochemical component 11. In addition, the mylar film 13 covers the plurality of electrochemical members 11 in a state where the plurality of electrochemical members 11 are stacked in the Z-axis direction, thereby bundling the electrochemical members 11. In other words, the plurality of electrochemical components 11 are housed in the cell casing 12 in a state of being covered with the mylar film 13. In addition, a slit through which a heat conductive member described later passes is provided in advance in the mylar film 13.

The cell cover 14 closes at least one side opening of the cell casing 12. In addition, the cell cover plate 14 is provided with a positive electrode terminal and a negative electrode terminal for connecting the positive electrode tab 112 and the negative electrode tab 113, and is used for connecting external leads.

The structure of the electrochemical component 11 is explained in detail below with reference to fig. 2. The left side in fig. 2 is a perspective view of the electrochemical component 11 and the right side in fig. 2 is a side view of the electrochemical component 11. As previously mentioned, the electrochemical component 11 is a jellyroll formed using a winding process or a laminate formed using a stacking process. The electrochemical member 11 includes: an electrochemical member main body 111, a cathode tab 112, an anode tab 113, and a heat conductive member 114.

The electrochemical device main body 111 is formed in a substantially flat shape by stacking and winding a negative electrode metal foil, a separator, a positive electrode metal foil, and a separator (i.e., a roll core), or stacking a negative electrode metal foil, a separator, a positive electrode metal foil, and a separator (i.e., a stack). In the present embodiment, a core is taken as an example for description. Due to the characteristics of the roll core process, the side edge of the formed electrochemical component main body 111 is arc-shaped.

The positive electrode tab 112 and the negative electrode tab 113 are connection terminals of the electrochemical component 11 to the outside, and are made of metal foils integrated with the metal foils in the positive electrode collector and the negative electrode collector, respectively. Specifically, in the production of the electrochemical component 11, when preparing metal foils of the positive electrode collector and the negative electrode collector, portions of the positive electrode tab 112 and the negative electrode tab 113 are reserved (pre-cut) in addition to the positive electrode collector and the negative electrode collector in the electrochemical component main body 111. After a winding core is formed through a winding process or a lamination is formed through a stacking process, the cathode tab 112 and the anode tab 113 are located outside the electrochemical member body 111 to function as external connection terminals.

The cathode tab 112 and the anode tab 113 are preferably located on the same side of the electrochemical member main body 111 from the viewpoint of facilitating connection to the outside. However, the arrangement of the cathode tab 112 and the anode tab 113 is not limited thereto, and may be located on different sides of the electrochemical member main body 111.

On the other hand, after a winding core is formed by a winding process or a lamination is formed by a stacking process, the positive electrode tab 112 and the negative electrode tab 113 are in a state in which metal foils are stacked in layers. In addition, since the positive electrode current collector and the negative electrode current collector are alternately stacked, the metal foil forming the positive electrode current collector and the metal foil forming the negative electrode current collector are also alternately stacked. Further, since the positive electrode tab 112 and the negative electrode tab 113 are formed of metal foils integrated with the metal foil of the positive electrode current collector and the metal foil of the negative electrode current collector, respectively, there is a slight gap between the plurality of metal foils forming the positive electrode tab 112 and the plurality of metal foils forming the negative electrode tab 113. From the viewpoint of stability and durability of the tabs, it is preferable that the metal foils of the positive electrode tab 112 and the negative electrode tab 113 are pinched together by welding to form a block-shaped tab.

The height of the positive electrode tab 112 and the negative electrode tab 113 protruding from the electrochemical component main body 111 is not limited as long as the positive electrode terminal and the negative electrode terminal of the cell cover 14 can be connected to each other. From the viewpoint of weight reduction of the battery cell, it is preferably about several millimeters.

Next, the heat conductive member 114 will be described in detail with reference to fig. 2. The heat conductive member 114 is preferably disposed at a side of the electrochemical member main body 111 opposite to a side at which the cathode tab 112 and the anode tab 113 are disposed. A part of the heat conductive member 114 is located inside the electrochemical device body 111, and the remaining part is located outside the electrochemical device body 111. The heat conductive member 114 is also formed of a metal foil. As the arrangement manner of the heat conductive member 114, a metal foil for forming the heat conductive member 114 may be inserted into metal foils forming the positive and negative electrode current collectors at each winding or stacking in a winding process of a winding core or a stacking process of stacked sheets. Therefore, the metal foil forming the heat conductive member 114 is also a multi-sheet stacked shape. In this case, a process of inserting the metal foil of the heat conductive member 114 is required in the process of manufacturing the winding core or the laminate.

On the other hand, in another aspect of the present embodiment, the heat conductive member 114 is formed of a metal foil integrated with the metal foil of the positive electrode current collector and/or the negative electrode current collector. That is, the positive electrode current collector (or the negative electrode current collector), the positive electrode tab (or the negative electrode tab), and the heat conductive member are formed of the same metal foil. In this case, a process of inserting the metal foil of the heat conductive member 114 is not required in the process of manufacturing the core or the laminate. However, in the preparation process of the metal foil, it is necessary to reserve (pre-cut) a portion for forming the heat conductive member 114 in addition to the positive electrode tab 112 and the negative electrode tab 113 described above.

In the present embodiment, as shown in the side view of fig. 2, the portion of the heat conductive member 114 protruding from the electrochemical member main body 111 is bent. In the mounted state, the heat conductive member 114 passes through the mylar film 13, and is in direct contact with the cell casing 12. Thereby, the heat inside the electrochemical member 11 can be efficiently conducted to the cell casing 12 via the heat conducting member 114. On the other hand, even in the case where the cell needs to be heated when the battery is first powered on in an extremely cold area or the like, the electrochemical member 11 can be quickly heated via the heat conductive member 114.

In addition, because the portion of the heat conducting member 114 protruding from the electrochemical component main body 111 is bent, the heat conducting member 114 is in surface contact with the cell casing 12, which effectively enlarges the heat conducting area, thereby improving the heat conducting efficiency. On the other hand, as described above, the heat conductive member 114 is provided on the opposite side of the electrochemical device main body 111 from the side where the cathode tab 112 and the anode tab 113 are provided. In the use state, the cathode tab 112 and the anode tab 113 are located at the upper side of the electrochemical member 11 in the direction of gravity, and the heat transfer member 114 is located at the lower side of the electrochemical member 11 in the direction of gravity. Therefore, the heat conductive member 114 can be press-fitted onto the bottom surface of the cell casing 12 by the gravity of the electrochemical member 11 itself, and the heat conductive performance of the heat conductive member 114 can be further ensured.

In addition, compared to the case where the heat conductive member 114 is formed by separately inserting a metal foil, forming the heat conductive member 114 by using a metal foil of the positive electrode current collector or the negative electrode current collector itself can reduce the weight of the electrochemical member 11 and avoid a decrease in the cell capacity. Further, the heat conductive member 114 is formed of a metal foil of the positive electrode current collector or the negative electrode current collector itself, and the heat inside the electrochemical device 11 can be conducted to the outside through the most direct path, thereby greatly improving the heat dissipation effect.

Further, in the case where the heat conductive member 114 is formed using a metal foil of the positive electrode current collector or the negative electrode current collector itself, the heat conductive member 114 may be formed using a metal foil of one of the positive electrode current collector and the negative electrode current collector. In this case, in the preparation step of the positive electrode current collector or the negative electrode current collector, a metal foil for forming the heat conductive member 114 is previously prepared (pre-cut) from a metal foil of one of the positive electrode current collector or the negative electrode current collector. As shown in fig. 2, the heat conductive member 114 is formed as a single heat conductive member.

In addition, as in the case of the positive electrode tab 112 and the negative electrode tab 113, from the viewpoint of stability and durability of the heat conductive member 114, it is preferable that the metal foils of the heat conductive member 114 are kneaded together by welding to form a block-shaped heat conductive member.

The inventor of the invention compares the effect difference of the invention and the prior art through CAE simulation. As shown in fig. 3, the left side of the figure shows the cell operating temperature simulation result of the structure in which the heat conductive member 114 of the present invention is disposed inside the electrochemical component 11 of the cell 1, and the right side of the figure shows the cell operating temperature simulation result of the prior art structure in which the heat conductive structure is disposed outside the cell. The main difference lies in that, in the prior art, the heat conduction structure is used between two or more electric cores, and the heat conduction structure and the electric cores are in a flat relationship, and the two are only related in physical form. Compared with external heat dissipation, the heat conducting member 114 is disposed inside the battery cell 1, especially inside the electrochemical component 11, so that the heat conducting capability of the battery can be greatly improved. Natural heat dissipation is the environmental condition with the weakest heat dissipation capability (environmental conditions are classified, natural heat dissipation is less than liquid cooling heat dissipation and is less than direct cooling heat dissipation).

Modification example 1

Fig. 4 shows a modification of the present embodiment. In the present modification, the heat conductive member 114-1 and the heat conductive member 114-2 are provided instead of the heat conductive member 114. In the foregoing embodiment, the heat conductive member 114 is formed using a metal foil of one of the positive electrode collector and the negative electrode collector. In the present modification, the heat conductive member 114-1 and the heat conductive member 114-2 are heat conductive members formed of a metal foil integral with the positive electrode current collector and a metal foil integral with the negative electrode current collector, respectively. That is, in the preparation step of the positive electrode current collector or the negative electrode current collector, the metal foils for forming the heat conductive members 114-1 and 114-2 are previously prepared (pre-cut) from both the metal foils of the positive electrode current collector or the negative electrode current collector. Thereby, the heat conductive members 114-1 and 114-2 corresponding to the positive electrode current collector (positive electrode tab 112) and the negative electrode current collector (negative electrode tab 113), respectively, are formed.

Further, in the present modification, since the heat conductive member 114-1 and the heat conductive member 114-2 are heat conductive members formed of a metal foil integral with the positive electrode current collector and a metal foil integral with the negative electrode current collector, respectively, a space is provided between the heat conductive member 114-1 and the heat conductive member 114-2, or an insulating material is provided therebetween, to prevent a short circuit between the positive electrode current collector and the negative electrode current collector.

In this case, the heat inside the electrochemical component 11 can also be efficiently conducted to the cell casing 12 via the heat conducting member 114-1 and the heat conducting member 114-2. Meanwhile, since the metal foils of both the positive electrode current collector and the negative electrode current collector are processed in the same manner, the production line can be shared, and the production process is simplified.

Embodiment 1 of the present invention and modification 1 thereof have been described above based on the case of a winding core. However, the invention can also be applied in the case of a laminate.

Modification 2

Next, another modification of the present embodiment will be described. Fig. 5 is a perspective view of the present modification.

In embodiment 1 and modification 1 described above, the description has been made based on the case of a core. The side edge of the winding core formed by the winding process is arc-shaped. On the other hand, the side edges of the laminations formed by the stacking process are right-angled. This modification is a modification of the manner of disposing the heat conductive member in the case of the laminated sheet.

As shown in fig. 5, in the present modification, a heat conductive member 114-3 is provided instead of the heat conductive member 114, as compared with embodiment 1. The heat conductive member 114-3 is provided at the side ridge of the electrochemical device main body 111, in addition to protruding from the opposite sides of the positive and negative electrode tabs 112 and 113. Therefore, the contact area of the heat-conducting member 114-3 and the cell casing 12 is further increased, and the heat-conducting effect is further improved.

Embodiment mode 2

Next, a battery cell according to embodiment 2 of the present invention will be described with reference to fig. 6. In embodiment 1 and its modified examples, the structure in which the heat conductive member is inserted into the electrochemical member 11 or the heat conductive member is formed by the metal foil itself of the positive electrode current collector and/or the negative electrode current collector of the electrochemical member 11 has been described. In this embodiment, a structure in which a heat conductive member is formed by a winding pin will be described.

Fig. 6 is a schematic view of the electrochemical device 11' of the present embodiment. In fig. 6, the positive electrode tab and the negative electrode tab are not shown. As shown in fig. 6, the cell structure of the present embodiment is the same as that of embodiment 1 except that an electrochemical member 11' is used instead of the electrochemical member 11 of embodiment 1, and therefore, redundant description is omitted.

The electrochemical device 11 'includes an electrochemical device main body 111' and a winding pin 115 (heat conduction member). The electrochemical device main body 111' is a winding core formed by stacking and winding a negative electrode metal foil, a separator, a positive electrode metal foil, and a separator, as in embodiment 1. In the winding process of the winding core, there is inevitably a winding needle as a reference for winding. In the manufacture of a typical cell or electrochemical component, the winding core needs to be pulled out after the winding process is completed. That is, in a process for manufacturing a general battery cell or electrochemical component, the winding pin is used as a recovery member. However, in the present embodiment, the winding needle 115 remains inside the electrochemical component 11 'after the winding process is completed, and serves as a component of the electrochemical component 11'.

As the winding needle, various patterns can be adopted. Depending on the form of the electrochemical component, needle-shaped winding needles, rod-shaped winding needles, plate-shaped winding needles, etc. may be used. In the description of the present embodiment, a plate-shaped winding needle is used as an example for description. However, other forms of needle wrap are certainly possible to practice the present invention.

In the present embodiment, the winding needle 115 is a plate-like winding needle and is made of an insulating material. In the present embodiment, the winding core 115 functions as a heat conductive member and is therefore made of a material having heat conductivity such as metal. The winding pin 115 also functions as a winding pin serving as a winding reference in the winding process of the electrochemical device 11'. The winding needle 115 includes a winding needle main body 115A and a winding needle foot 115B. The needle winding body 115A is formed in a panel shape, is a reference for winding the electrochemical device 11 ', and corresponds to a portion of the heat transfer member inserted into the electrochemical device 11'. The winding pin 115B is bent from one end of the winding pin body 115A in a direction perpendicular to the winding pin body. The number of the winding stitches 115B may be 1, or may be plural, and the direction of bending is not limited, and all the stitches may be bent toward the same side, or a part of the stitches may be bent in the opposite direction with respect to the other part. In the state in which the electrochemical component 11' is mounted in the cell casing 12, the winding pins 115B are in direct contact with the cell casing 12 through the mylar film 13. Therefore, the winding pins 115B correspond to portions of the heat conductive member protruding from the electrochemical device 11'.

According to the present embodiment, the winding pin used in the winding process of the winding core is used as the heat conductive member. Therefore, the heat conductive member can be formed without an additional process. The winding pin 115 is a reference for winding the electrochemical component 11 'and is a member in which the positive electrode current collector and the negative electrode current collector are most closely contacted, and therefore, the heat inside the electrochemical component 11' can be efficiently conducted to the outside through the most direct path. That is, a direct heat conduction path of the winding needle main body 115A → the winding pin 115B → the cell casing 12 can be formed. In addition, by bending the winding pin 115B from one end of the winding pin body 115A in a direction perpendicular to the winding pin body, the winding pin 115B can be brought into surface contact with the cell casing 12, and the heat conduction effect is further improved.

It should be understood that the above-mentioned embodiments are only for explaining the present invention, and the protection scope of the present invention is not limited thereto, and any person skilled in the art should be able to cover the technical scope of the present invention/utility model, the technical solutions according to the present invention/utility model and the inventive concept equivalent substitutions or changes thereof within the protection scope of the present invention/utility model.