阅读说明：本技术 蓄电装置 (Electricity storage device ) 是由 米山显启 田岛光俊 乘峰笙汰 于 2020-03-17 设计创作，主要内容包括：蓄电装置包括：壳体,其具有端子配置部；一对输出端子,其设于端子配置部；电极体,其收纳于壳体；一对集电部,其将电极体和一对输出端子电连接；以及绝缘性的电极体保持件,其抵接于电极体的在一对集电部排列的第1方向X上相对的一对第1面,固定于壳体并在第1方向X上夹持电极体。(The power storage device includes: a housing having a terminal arrangement portion; a pair of output terminals provided at the terminal arrangement portion; an electrode body housed in the case; a pair of current collecting units for electrically connecting the electrode body and the pair of output terminals; and an insulating electrode body holder that is in contact with a pair of 1 st surfaces of the electrode body facing in the 1 st direction X in which the pair of current collecting portions are arranged, is fixed to the case, and sandwiches the electrode body in the 1 st direction X.)

1. An electric storage device is characterized in that,

the power storage device includes:

a housing having a terminal arrangement portion;

a pair of output terminals provided at the terminal arrangement portion;

an electrode body housed in the case;

a pair of current collecting units that electrically connect the electrode body and the pair of output terminals; and

and an insulating electrode body holder that is in contact with a pair of 1 st surfaces of the electrode body that face in a 1 st direction in which the pair of current collecting portions are arranged, is fixed to the case, and sandwiches the electrode body in the 1 st direction.

2. The power storage device according to claim 1,

the electrode body holder has a 2 nd plate portion and a pair of 1 st plate portions, the pair of 1 st plate portions being in contact with the pair of 1 st surfaces, the 2 nd plate portion being formed integrally with each 1 st plate portion, interposed between the terminal arrangement portion and the electrode body, and fixed to the terminal arrangement portion.

3. The power storage device according to claim 2,

the collector unit has a collector plate fixed to the terminal arrangement unit and a strip-shaped collector sheet connecting the electrode body to the collector plate,

the 2 nd plate portion is interposed between the terminal arrangement portion and the current collecting plate to electrically insulate them.

4. The power storage device according to claim 2,

the thickness of the 2 nd plate portion is larger than the thickness of the 1 st plate portion.

5. The power storage device according to claim 4,

the 2 nd plate portion abuts against the terminal arrangement portion and the electrode body.

6. The power storage device according to any one of claims 2 to 5,

the electrode body holder has a notch portion in a region facing the electrode body side of a connection portion between the 1 st plate portion and the 2 nd plate portion.

7. The power storage device according to any one of claims 1 to 6,

the electrode body holder is constituted by a pair of holder units,

one of the holder units abuts against one of the 1 st surfaces and is fixed to the housing,

the other holder unit abuts against the other 1 st surface and is fixed to the housing.

8. The power storage device according to any one of claims 1 to 7,

the pair of 1 st surfaces extend in a direction intersecting the terminal arrangement portion,

the electrode body has a 2 nd surface connecting end portions of the pair of 1 st surfaces on a side opposite to the terminal arrangement portion to each other,

the power storage device includes a 2 nd electrode body holder other than the 1 st electrode body holder as the electrode body holder according to any one of claims 1 to 6, the 2 nd electrode body holder having a 4 th plate portion and a pair of 3 rd plate portions, the pair of 3 rd plate portions being in contact with the pair of 1 st surfaces, the 4 th plate portion being in contact with the 2 nd surface and being connected to the pair of 3 rd plate portions.

Technical Field

The present disclosure relates to an electrical storage device.

Background

For example, as a power supply requiring a high output voltage for a vehicle or the like, a power storage module having an assembly in which a plurality of power storage devices (for example, batteries) are connected in series is known. The power storage device used in such a power storage module generally includes: an outer can having an opening; an electrode body housed in the outer can; a sealing plate for sealing the opening of the outer can; a pair of output terminals provided on the sealing plate; and a current collecting tab that electrically connects the electrode body and the pair of output terminals (see, for example, patent document 1).

Documents of the prior art

Patent document

Patent document 1: japanese unexamined patent publication No. 2011-

Disclosure of Invention

Problems to be solved by the invention

In the electric storage device, the electrode assembly is generally used in a smaller size than the internal space of the outer can in consideration of workability when the electrode assembly is housed in the outer can. However, if a dimensional difference occurs between the outer can and the electrode body, a space is likely to be generated between the outer can and the electrode body. Further, when a force is applied to the power storage device in a state where a space exists between the outer can and the electrode assembly, the electrode assembly may be easily displaced with respect to the outer can. When the electrode body is displaced with respect to the outer can, a force due to the displacement of the electrode body is applied to the current collecting tab, the current collecting tab is broken, and the reliability of the power storage device may be lowered.

The present disclosure has been made in view of such circumstances, and an object thereof is to provide a technique for improving the reliability of an electric storage device.

Means for solving the problems

One aspect of the present disclosure is an electrical storage device. The power storage device includes: a housing having a terminal arrangement portion; a pair of output terminals provided at the terminal arrangement portion; an electrode body housed in the case; a pair of current collecting units for electrically connecting the electrode body and the pair of output terminals; and an insulating electrode body holder that abuts a pair of 1 st surfaces of the electrode body facing in the 1 st direction in which the pair of current collecting portions are arranged, is fixed to the case, and sandwiches the electrode body in the 1 st direction.

Any combination of the above components and a technical means obtained by converting the expression of the present disclosure between a method, an apparatus, a system, and the like are also effective as technical means of the present disclosure.

ADVANTAGEOUS EFFECTS OF INVENTION

According to the present disclosure, the reliability of the power storage device can be improved.

Drawings

Fig. 1 is a perspective view of a power storage device according to embodiment 1.

Fig. 2 is a cross-sectional view of a region of the power storage device including a pair of output terminals.

Fig. 3 (a) is a perspective view of one holder unit as viewed from obliquely above, and fig. 3 (B) is a perspective view of one holder unit as viewed from obliquely below.

Fig. 4 is a sectional view of a region of the power storage device including one holder unit.

Fig. 5 (a) is a perspective view of the other holder unit as viewed from obliquely above, and fig. 5 (B) is a perspective view of the other holder unit as viewed from obliquely below.

Fig. 6 is a perspective view of the power storage device according to embodiment 2.

Fig. 7 is a side view of the power storage device.

Fig. 8 is an enlarged perspective view of a region of the electrode body holder including the notch portion.

Fig. 9 (a) is a perspective view of a power storage device according to modification 1. Fig. 9 (B) is a perspective view of the 2 nd electrode body holder.

Detailed Description

Hereinafter, the power storage device of the present disclosure will be described based on preferred embodiments with reference to the drawings. The embodiments are not intended to limit the invention but to exemplify the invention, and all the features and combinations described in the embodiments are not necessarily essential features and combinations of the invention. The same or equivalent constituent elements, members, and processes shown in the respective drawings are denoted by the same reference numerals, and overlapping descriptions are appropriately omitted. The proportions and shapes of the respective portions shown in the drawings are set for easy and convenient explanation, and are not to be construed in a limiting manner unless otherwise specified. In addition, when the terms "1 st", "2 nd", and the like are used in the present specification or claims, they do not denote any order or importance, but rather are used to distinguish one structure from another structure, unless otherwise specified. In the drawings, some components that are not important to explain the embodiments are omitted.

Fig. 1 is a perspective view of a power storage device 1 according to embodiment 1. Fig. 2 is a cross-sectional view of a region including a pair of output terminals of the power storage device 1. Fig. 1 shows a state in which the inside of power storage device 1 is seen through. In fig. 1 and 2, the electrode body 6 is schematically illustrated.

The power storage device 1 is a rechargeable secondary battery such as a lithium ion battery, a nickel hydrogen battery, or a nickel cadmium battery, or a capacitor. The power storage device 1 is a so-called prismatic battery. The power storage device 1 includes a case 2, a pair of output terminals 4, an electrode body 6, a pair of current collecting portions 8, and an electrode body holder 10.

The case 2 has a flat rectangular parallelepiped shape and includes an outer can 12 and a sealing plate 14. The outer can 12 is, for example, a bottomed cylindrical shape and has a rectangular opening 12 a. The electrode body 6, the electrolyte solution, and the like are housed in the outer can 12 through the opening 12 a. The sealing plate 14 is a rectangular plate, and closes the opening 12a to seal the outer can 12. The outer can 12 and the sealing plate 14 are electrically conductive and are made of metal such as aluminum, iron, or stainless steel. The opening 12a of the outer can 12 and the peripheral edge of the sealing plate 14 are joined by, for example, laser welding.

The sealing plate 14 is provided with a pair of output terminals 4. Thus, the sealing plate 14 constitutes a terminal arrangement portion. Specifically, the sealing plate 14 has a positive output terminal 4 near one end in the longitudinal direction and a negative output terminal 4 near the other end. Hereinafter, the positive output terminal 4 is referred to as a positive terminal 4a, and the negative output terminal 4 is referred to as a negative terminal 4b, as appropriate. When it is not necessary to distinguish the polarity of the output terminal 4, the positive terminal 4a and the negative terminal 4b are collectively referred to as the output terminal 4. The pair of output terminals 4 are inserted through holes 14a formed in the sealing plate 14. An insulating sealing member 16 is interposed between the pair of output terminals 4 and the through holes 14 a.

Further, a safety valve 18 is provided between the pair of output terminals 4 of the sealing plate 14. Further, the relief valve 18 may not be provided. The safety valve 18 is configured to open when the internal pressure of the case 2 rises to a predetermined value or more, and release the gas inside the case 2. The safety valve 18 is constituted by, for example, a thin portion having a thickness smaller than that of other portions provided in a part of the sealing plate 14, and a linear groove formed in a surface of the thin portion. In this structure, when the internal pressure of the case 2 rises, the thin portion opens with the groove as a starting point, and the valve opens. The safety valve 18 is not limited to the above-described irreversible valve, and may be a self-recovery type exhaust valve that is re-closed when the pressure in the case 2 becomes a certain value or less after the valve is opened.

Further, a liquid inlet 20 is provided between the pair of output terminals 4 of the sealing plate 14. The pour hole 20 is used when the electrolyte is poured into the case 2. In an example of the assembly process of the power storage device 1, after the electrode body 6 is housed in the outer can 12, the outer can 12 and the sealing plate 14 are laser welded. Then, the electrolyte is injected into the casing 2 through the injection hole 20. After the electrolyte solution is injected, a liquid injection plug (not shown) is joined to the liquid injection hole 20 by laser welding or the like. The pour hole 20 may be closed by caulking a rivet-type pour plug to the pour hole 20, or may be closed by pressing a pour plug made of an elastic material into the pour hole 20.

In the description of the present embodiment, for convenience of description, the surface on which sealing plate 14 (terminal arrangement portion) is provided is referred to as the upper surface of power storage device 1, and the opposite surface is referred to as the bottom surface of power storage device 1. Power storage device 1 has 4 side surfaces connecting the top surface and the bottom surface. Two sides of the 4 sides are a pair of long sides connected to the long sides of the upper and bottom surfaces. The long side surface is a main surface that is the largest area of the 6 surfaces of the power storage device 1. The remaining two side surfaces other than the two long side surfaces are a pair of short side surfaces connected to the short sides of the upper surface and the bottom surface of the power storage device 1. These directions and positions are specified for convenience. Therefore, for example, in the present disclosure, the portion defined as the upper surface does not necessarily mean the portion located above the portion defined as the bottom surface.

The direction in which a pair of current collecting tabs 24 (or the width direction of the main surfaces of the current collecting tabs 24) to be described later are arranged is defined as a 1 st direction X, the direction in which a pair of long side surfaces are arranged (or the stacking direction of a plurality of electrode plates constituting the electrode body 6) is defined as a 2 nd direction Y, and the direction in which the upper surface and the bottom surface are arranged is defined as a 3 rd direction Z. In the present disclosure, the direction in which the current collecting tabs 24 are arranged may be the direction in which the current collecting tabs 24 are arranged when the electrode body 6 is viewed from the 2 nd direction. That is, the direction in which the virtual straight line connecting the collector tabs 24 extends is not necessarily shown.

The case 2 houses an electrode body 6, a pair of current collecting portions 8, and an electrode body holder 10. The electrode body 6 is an electrode group having a structure in which a plurality of electrode plates are stacked. Specifically, the electrode body 6 has a structure in which positive electrode plates, which are positive electrode plates, and negative electrode plates, which are negative electrode plates, are alternately stacked. A plate separator is interposed between adjacent positive and negative plates. In the present embodiment, two electrode bodies 6 are arranged in the 2 nd direction Y and housed in the case 2 (see fig. 4).

As an example, the positive electrode plate includes a positive electrode current collector formed of a metal foil, and a positive electrode active material layer (positive electrode mixture layer) containing a positive electrode active material laminated on a surface of the positive electrode current collector. The negative electrode plate has a negative electrode current collector formed of a metal foil and a negative electrode active material layer (negative electrode mixture layer) containing a negative electrode active material laminated on the surface of the negative electrode current collector. The positive electrode collector and the negative electrode collector each have an electrode portion on which the mixture layers of the respective electrodes are laminated and a tab portion that extends from an edge of the electrode portion and constitutes a current collecting tab 24 described later.

Each electrode body 6 has a shape substantially similar to the case 2. Therefore, each electrode body 6 has an upper surface facing the sealing plate 14 of the case 2, a bottom surface facing the bottom surface of the case 2, a pair of long side surfaces facing the pair of long side surfaces of the case 2, and a pair of short side surfaces facing the pair of short side surfaces of the case 2. A predetermined gap is provided between each surface of the case 2 and each surface of the electrode body 6.

The electrode body 6 and the pair of output terminals 4 are electrically connected by a pair of current collecting portions 8. Collector 8 includes a positive collector 8a electrically connected to positive terminal 4a and a negative collector 8b electrically connected to negative terminal 4 b. Hereinafter, when it is not necessary to distinguish the polarity of the current collecting portion 8, the positive electrode current collecting portion 8a and the negative electrode current collecting portion 8b are collectively referred to as the current collecting portion 8.

Each collector 8 includes a collector plate 22 and a collector tab 24. The collector plate 22 is fixed to the sealing plate 14 (terminal arrangement portion). Specifically, each current collector plate 22 is disposed on the surface of the sealing plate 14 facing the inside of the case 2 through a second plate portion 28, which will be described later, of the electrode body holder 10, and is fixed to the sealing plate 14 through each output terminal 4. In this state, the collector plates 22 are electrically connected to the ends of the output terminals 4 located in the case 2.

The current collecting tab 24 is a strip-shaped (tongue-shaped) portion that connects the electrode body 6 and the current collecting plate 22. The collector tab 24 extends from each electrode plate of the electrode body 6 and is connected to the collector plate 22. Current collecting tab 24 includes a positive tab 24a extending from the positive electrode plate and a negative tab 24b extending from the negative electrode plate. A positive electrode tab 24a extending from the positive electrode plate is connected to the collector plate 22 fixed to the positive electrode terminal 4 a. A negative electrode tab 24b extending from the negative electrode plate is connected to the current collecting plate 22 fixed to the negative electrode terminal 4 b. Hereinafter, when it is not necessary to distinguish the polarity of the current collecting tab 24, the positive electrode tab 24a and the negative electrode tab 24b are collectively referred to as the current collecting tab 24. The current collecting tabs 24 are bundled together with the current collecting tabs 24 of the same polarity to form a current collecting tab laminate. The laminated body is joined to the current collector plate 22 by ultrasonic welding, laser welding, or the like.

Note that, the positive-side current collector plate 22 and the negative-side current collector plate 22 may be formed of one plate material, or may be formed by combining a plurality of plate materials. When the current collector plate 22 is formed of a plurality of plate materials, the plurality of plate materials can be divided into a plate material to which the current collector tabs 24 are joined and a plate material connected to the output terminal 4. This allows the step of joining collector tab 24 to collector plate 22 and the step of joining output terminal 4 to collector plate 22 to be performed simultaneously. For example, the plate materials are joined to each other after the two steps are completed.

Each collector tab 24 is disposed such that the main surface 24c faces the 2 nd direction Y intersecting the 1 st direction X in which the pair of collector portions 8 are arranged. That is, the end portion of each collector sheet 24 on the electrode body 6 side extends along the 1 st direction X. The end on the collector plate 22 side also extends in the 1 st direction X. The collector tab 24 extends toward the collector plate 22 while being bent in the 2 nd direction Y, and is connected to the collector plate 22. Therefore, the main surface 24c of the current collecting tab 24 faces the sealing plate 14 in the 2 nd direction Y in a partial region and in the 3 rd direction Z in another partial region. The current collecting tab 24 may not be formed by tabs included in the positive electrode current collector and the negative electrode current collector. For example, the current collecting tab 24 may be formed of a conductive member independent of the positive electrode current collector and the negative electrode current collector, and the conductive member may be bonded to the positive electrode current collector and the negative electrode current collector, respectively.

The displacement of the electrode body 6 inside the case 2 is restricted by the electrode body holder 10. The electrode body holder 10 is in contact with a pair of first surfaces 6a of the electrode body 6 facing in the 1 st direction X in which the pair of current collecting portions 8 are arranged. The pair of 1 st surfaces 6a of the electrode body 6 are a pair of short side surfaces extending in a direction intersecting the terminal arrangement portion. The electrode body holder 10 is fixed to the case 2 and sandwiches the electrode body 6 in the 1 st direction X. Thereby, displacement of the electrode body 6 in the 1 st direction X is suppressed. In addition, the electrode body 6 is sandwiched by the electrode body holder 10 in the 1 st direction X, so that the displacement of the electrode body 6 in the 2 nd direction Y and the displacement in the 3 rd direction Z are also suppressed to a large extent.

The electrode body holder 10 has insulation properties. For example, the electrode body holder 10 is formed of a thermoplastic resin having insulating properties, such as polypropylene (PP), polybutylene terephthalate (PBT), Polycarbonate (PC), and NORYL (registered trademark) resin (modified PPE). Further, the rigidity of the electrode body holder 10 is preferably higher than the rigidity of the current collecting tab 24.

The electrode body holder 10 of the present embodiment includes the 2 nd plate portion 28 and the pair of 1 st plate portions 26. The pair of 1 st plate portions 26 extend in the 3 rd direction Z and abut against the pair of 1 st surfaces 6 a. Specifically, a predetermined gap is provided between the pair of 1 st surfaces 6a of the electrode body 6 and the pair of short side surfaces of the case 2. One 1 st plate portion 26 is interposed between the 1 st surface 6a on the positive electrode terminal 4a side and the short side surface of the case 2 opposite to the 1 st surface 6a, and abuts on the 1 st surface 6 a. The other 1 st plate 26 is interposed between the 1 st surface 6a on the negative electrode terminal 4b side and the short side surface of the case 2 opposite to the 1 st surface 6a, and abuts on the 1 st surface 6 a. Further, each of the 1 st plate portions 26 of the present embodiment is separated from each of the short side surfaces of the case 2. This can more reliably suppress contact between the electrode body 6 and the case 2.

The 2 nd plate portion 28 is formed integrally with each 1 st plate portion 26. The 1 st plate portion 26 and the 2 nd plate portion 28 of the present embodiment are integrally molded resin. The 2 nd plate portion 28 is interposed between the sealing plate 14 (terminal arrangement portion) and the electrode body 6, and is fixed to the sealing plate 14. The 2 nd plate portion 28 has a through hole 28a at a position overlapping each output terminal 4 when viewed from the 3 rd direction Z. The through hole 28a is penetrated by an end portion of each output terminal 4 located in the housing 2. Therefore, the 2 nd plate portion 28 is fixed to the sealing plate 14 via the output terminals 4. Further, the 2 nd plate portion 28 is interposed between the sealing plate 14 (terminal disposition portion) and the current collecting plate 22 to electrically insulate them. That is, the 2 nd plate portion 28 also functions as an insulating member for electrically insulating the sealing plate 14 from the current collecting plate 22.

The 2 nd plate portion 28 is divided into a portion to which one 1 st plate portion 26 is connected on the positive electrode terminal 4a side and a portion to which the other 1 st plate portion 26 is connected on the negative electrode terminal 4b side. That is, the electrode body holder 10 of the present embodiment is configured by a pair of holder units 10a and 10b arranged in the 1 st direction X. The pair of holder units 10a, 10b have the 1 st plate portion 26 and the 2 nd plate portion 28, respectively. One holder unit 10a abuts on the first 1 st surface 6a of the electrode body 6 and is fixed to the case 2. The other holder unit 10b abuts on the other 1 st surface 6a of the electrode body 6 and is fixed to the case 2.

More specifically, the 1 st plate portion 26 of one holder unit 10a abuts on the 1 st surface 6a on the positive electrode terminal 4a side. The 2 nd plate portion 28 of one holder unit 10a is fixed to the sealing plate 14 via the positive electrode terminal 4 a. That is, the positive electrode terminal 4a penetrates the 2 nd plate portion 28 and the current collecting plate 22 in a state where the 2 nd plate portion 28 is sandwiched between the sealing plate 14 and the current collecting plate 22. The end of the positive electrode terminal 4a on the electrode side is caulked, whereby the 2 nd plate portion 28 and the current collecting plate 22 are fixed to the sealing plate 14. Current collector plate 22 and sealing plate 14 are insulated by second plate portion 28 interposed therebetween.

The 1 st plate portion 26 of the other holder unit 10b abuts the other 1 st surface 6a on the negative electrode terminal 4b side. The 2 nd plate portion 28 of the other holder unit 10b is fixed to the sealing plate 14 via the negative electrode terminal 4 b. That is, the negative electrode terminal 4b penetrates the 2 nd plate portion 28 and the current collecting plate 22 in a state where the 2 nd plate portion 28 is sandwiched between the sealing plate 14 and the current collecting plate 22. The end of the negative electrode terminal 4b on the electrode side is caulked, whereby the 2 nd plate portion 28 and the current collecting plate 22 are fixed to the sealing plate 14. Current collector plate 22 and sealing plate 14 are insulated by second plate portion 28 interposed therebetween. Thus, the pair of 1 st surfaces 6a of the electrode body 6 is sandwiched by the holder unit 10a and the holder unit 10b in the 1 st direction X.

Fig. 3 (a) is a perspective view of one holder unit 10a viewed from obliquely above, and fig. 3 (B) is a perspective view of one holder unit 10a viewed from obliquely below. In the holder unit 10a, the 1 st plate portion 26 and the 2 nd plate portion 28 are connected at right angles, and have an L-shape when viewed from the 2 nd direction Y.

The 1 st plate 26 has a reinforcing rib 30 on a surface 26a facing the electrode body 6 side. The 1 st plate portion 26 of the present embodiment has, for example, 3 reinforcing ribs 30. The 3 reinforcing ribs 30 are arranged at predetermined intervals in the 2 nd direction Y, and extend in the 3 rd direction Z from the lower end to the upper end of the 1 st plate portion 26, respectively. At the upper end of each reinforcing rib 30, a projection 30a extending along a surface 28b of the 2 nd plate 28 facing the electrode body 6 is provided. That is, the protruding portion 30a of the reinforcing rib 30 constitutes a triangular rib fixed to the surface 26a of the 1 st plate portion 26 facing the electrode body 6 side and the surface 28b of the 2 nd plate portion 28 facing the electrode body 6 side at the connecting portion 32 between the 1 st plate portion 26 and the 2 nd plate portion 28. By providing the reinforcing ribs 30, the rigidity of the retainer unit 10a can be improved. This can more reliably suppress displacement of the electrode body 6 in the 1 st direction X. In addition, the number of the reinforcing ribs 30 may be not 3, and may be one or more. In addition, the reinforcing rib 30 may also protrude from a region of the 1 st wall portion 34 that is opposite to the connecting portion 32. In addition, the shape of the projection 30a may be curved at the hypotenuse portion of the triangular rib.

The 2 nd plate portion 28 has a plurality of 1 st wall portions 34 protruding toward the electrode body 6 side. The 2 nd plate portion 28 of the present embodiment has 4 1 st wall portions 34. The two 1 st wall portions 34 are provided on both sides of the 2 nd plate portion 28 extending in the 1 st direction X. One 1 st wall portion 34 is provided on a side extending in the 2 nd direction Y at an end portion of the 2 nd plate portion 28 on the opposite side to the connecting portion 32. The remaining one of the first wall portions 34 is provided in a region between the connection portion 32 of the surface 28b facing the electrode body 6 side and the through hole 28 a. Thus, two 1 st wall portions 34 extend along the 1 st direction X, and two 1 st wall portions 34 extend along the 2 nd direction Y. The 4 1 st wall portions 34 are continuous at their ends to form a rectangular frame when viewed from the 3 rd direction Z. The 4 1 st wall portions 34 surround the periphery of current collector plate 22 in a state where holder unit 10a and current collector plate 22 are fixed to sealing plate 14. By providing the 1 st wall portion 34, contact between the current collecting plate 22 and the outer can 12 and the sealing plate 14 can be more reliably suppressed. Further, the 2 nd plate portion 28 of the holder unit 10a may also have a projection on the upper surface thereof. The sealing plate 14 may have a recess at a position corresponding to the protrusion. The protrusion and the recess are fitted to each other, thereby preventing the holder unit 10a from rotating about the positive electrode terminal 4 a. Therefore, the holder unit 10a can be easily aligned with the sealing plate 14 and the holder unit 10 b.

Further, the end portion of the 2 nd plate portion 28 on the opposite side to the connection portion 32 has a concave portion 36 that is curved outward in the 1 st direction X of the power storage device 1. The recess 36 is disposed so as to overlap with an edge of the safety valve 18 when viewed from the 3 rd direction Z. That is, by providing the concave portion 36, it is possible to avoid a partial blockage of the safety valve 18 by the holder cell 10 a.

The 2 nd plate portion 28 has a through hole 38 at a position overlapping the pouring hole 20 when viewed in the 3 rd direction Z. By providing the through-hole 38, the pouring hole 20 can be prevented from being closed by the holder unit 10 a. The 2 nd plate portion 28 has a 2 nd wall portion 40 surrounding the outer periphery of the through hole 38 at the peripheral edge portion of the through hole 38 on the surface 28b facing the electrode body 6 side. The 2 nd wall portion 40 protrudes toward the electrode body 6 side from the surface 28b facing the electrode body 6 side.

Fig. 4 is a sectional view of a region of the power storage device 1 including one holder unit 10 a. In fig. 4, the electrode body 6 is schematically illustrated. The current collector plate 22 has a through-hole 42 at a position overlapping the pouring hole 20 when viewed in the 3 rd direction Z. By providing the through-hole 42, the filling hole 20 can be prevented from being closed by the current collecting plate 22. In addition, in a state where holder unit 10a and collector plate 22 are fixed to sealing plate 14, second wall portion 2 40 is inserted into through hole 42. The 2 nd wall portion 40 protrudes in the 3 rd direction Z to the electrode body 6 side of the current collecting plate 22. The 2 nd wall portion 40 suppresses displacement of the current collecting tab 24 to a region overlapping the liquid pouring hole 20 when viewed from the 3 rd direction Z. As a result, the liquid inlet 20 can be prevented from being blocked by the current collecting tab 24.

Fig. 5 (a) is a perspective view of the other holder unit 10B as viewed from obliquely above, and fig. 5 (B) is a perspective view of the other holder unit 10B as viewed from obliquely below. The 1 st plate portion 26 and the 2 nd plate portion 28 of the retainer unit 10b are connected at right angles, and have an L-shape when viewed from the 2 nd direction Y. Similarly to the holder unit 10a, the 1 st plate 26 has a reinforcing rib 30 on a surface 26a facing the electrode body 6 side. The reinforcing rib 30 has a projection 30a at an upper end thereof, which extends along a surface 28b of the 2 nd plate 28 facing the electrode body 6. By providing the reinforcing ribs 30, the rigidity of the retainer unit 10b can be improved. This can more reliably suppress displacement of the electrode body 6 in the 1 st direction X. As in the holder unit 10a, the number of the reinforcing ribs 30 may be not 3, and may be one or more. In addition, the reinforcing rib 30 may also protrude from a region of the 1 st wall portion 34 that is opposite to the connecting portion 32. In addition, the shape of the projection 30a may be curved at the hypotenuse portion of the triangular rib.

Like the holder unit 10a, the 2 nd plate portion 28 includes a plurality of 1 st wall portions 34 protruding toward the electrode body 6 side. The two 1 st wall portions 34 are provided on both sides of the 2 nd plate portion 28 extending in the 1 st direction X. One 1 st wall portion 34 is provided on a side extending in the 2 nd direction Y at an end portion of the 2 nd plate portion 28 on the opposite side to the connecting portion 32. The remaining one of the first wall portions 34 is provided in a region between the connection portion 32 of the surface 28b facing the electrode body 6 side and the through hole 28 a. The plurality of 1 st wall portions 34 surround the periphery of current collector plate 22 in a state where holder unit 10b and current collector plate 22 are fixed to sealing plate 14. By providing the 1 st wall portion 34, contact between the current collecting plate 22 and the outer can 12 and the sealing plate 14 can be more reliably suppressed. Further, similarly to the holder unit 10a, the 2 nd plate portion 28 of the holder unit 10b may have a projection on the upper surface thereof. The sealing plate 14 may have a recess at a position corresponding to the protrusion. The protrusion and the recess are fitted to each other, thereby preventing the holder unit 10b from rotating about the negative electrode terminal 4 b. Therefore, the holder unit 10b can be easily aligned with the sealing plate 14 and the holder unit 10 a.

As described above, the power storage device 1 of the present embodiment includes: a housing 2 having a terminal arrangement portion; a pair of output terminals 4 provided at the terminal arrangement portion; an electrode body 6 housed in the case 2; a pair of current collecting units 8 for electrically connecting the electrode body 6 and the pair of output terminals 4; and an insulating electrode body holder 10 that is in contact with a pair of 1 st surfaces 6a of the electrode body 6 that face in the 1 st direction X in which the pair of current collecting portions 8 are arranged, is fixed to the case 2, and sandwiches the electrode body 6 in the 1 st direction X.

As a method of suppressing expansion of the power storage device 1, in other words, expansion of the case 2, it is conceivable to provide a space that allows expansion of the electrode body 6 between the case 2 and the electrode body 6. By providing a space between the case 2 and the electrode body 6, at least a part of the expansion of the electrode body 6 can be absorbed by the space, and therefore, the expansion of the power storage device 1 can be suppressed. As a result, the increase in the internal volume of the power storage device can be suppressed, and the decrease in the capacitance, the increase in the internal resistance, and the like of the power storage device 1 can be suppressed. In addition, damage and the like of the joint portion between the outer can 12 and the sealing plate 14 can also be suppressed. Therefore, the reliability of the power storage device 1 can be improved. Further, by making the size of the electrode assembly 6 smaller than the size of the internal space of the case 2 to form a space therebetween, it is possible to reduce the resistance such as friction received by the electrode assembly 6 from the case 2 when the electrode assembly 6 is housed in the case 2. This improves workability when the electrode assembly 6 is housed in the case 2.

However, if a space is provided between the case 2 and the electrode body 6, the electrode body 6 is easily displaced with respect to the case 2 when the power storage device 1 vibrates. If the electrode body 6 is displaced relative to the case 2, there is a risk that: stress concentrates on the current collecting tab 24 connecting the electrode body 6 and the output terminal 4, and fatigue failure occurs in the current collecting tab 24. In particular, the main surface 24c of the collector tab 24 faces the 2 nd direction Y or the 3 rd direction Z intersecting the 1 st direction X in which the pair of output terminals 4 are aligned. Therefore, the collector tabs 24 are less likely to be displaced in the 1 st direction X than in the other directions. Thus, when the electrode body 6 is displaced in the 1 st direction X, fatigue fracture is more likely to occur in the current collecting tab 24.

In contrast, in the power storage device 1 of the present embodiment, the electrode assembly 6 is sandwiched in the 1 st direction X by the electrode assembly holder 10 fixed to the case 2. This can suppress displacement of the electrode body 6 with respect to the case 2 when the power storage device 1 vibrates. In particular, displacement of the electrode body 6 in the 1 st direction X can be effectively suppressed. Therefore, the load applied to the current collecting tab 24 connecting the output terminal 4 and the electrode body 6 can be reduced. Therefore, a space can be provided between the case 2 and the electrode assembly 6 to suppress expansion of the power storage device 1, and the electrical connection state between the electrode assembly 6 and the output terminal 4 can be stably maintained. In particular, since the electrode body holder 10 and the current collecting tab 24 are both fixed to the electrode body 6 and the terminal arrangement portion, the load applied to the current collecting tab 24 by the electrode body holder 10 can be more reliably reduced.

That is, according to the present embodiment, the reliability of the power storage device 1 can be improved in terms of suppressing expansion of the power storage device 1 and stably maintaining the connection state between the electrode body 6 and the output terminal 4. In addition, the power storage device 1 can have a high capacitance while maintaining the reliability of the power storage device 1.

The electrode body holder 10 includes a pair of 1 st plate portions 26 and a 2 nd plate portion 28, the pair of 1 st plate portions 26 being in contact with the pair of 1 st surfaces 6a of the electrode body 6, and the 2 nd plate portion 28 being formed integrally with each 1 st plate portion 26, interposed between the terminal arrangement portion and the electrode body 6, and fixed to the terminal arrangement portion. This can more reliably suppress displacement of the electrode body 6 in the 1 st direction X.

The current collecting unit 8 has a current collecting plate 22 fixed to the terminal arrangement portion. The 2 nd plate portion 28 is interposed between the terminal disposition portion and the current collecting plate 22 to electrically insulate them. That is, the electrode body holder 10 of the present embodiment also functions as an insulating member that insulates the terminal arrangement portion and the current collecting plate 22. Thus, by providing the electrode body holder 10, an increase in the number of components of the power storage device 1 can be suppressed. Further, complication of the structure of the power storage device 1 can be suppressed. Further, complication of the assembly process of the power storage device 1 can be suppressed.

The electrode body holder 10 is constituted by a pair of holder units 10a and 10b, one holder unit 10a is fixed to the case 2 in contact with the first 1 st surface 6a of the electrode body 6, and the other holder unit 10b is fixed to the case 2 in contact with the second 1 st surface 6a of the electrode body 6. That is, the pair of holder units 10a and 10b are arranged at intervals in the 1 st direction X and are fixed to the housing 2. This can more reliably suppress displacement of the electrode body 6 in the 1 st direction X.

(embodiment mode 2)

Embodiment 2 has a structure common to embodiment 1 except for the shape of the electrode body holder. Hereinafter, the present embodiment will be described mainly with respect to the structure different from embodiment 1, and the common structure will be briefly described or omitted. Fig. 6 is a perspective view of the power storage device according to embodiment 2. Fig. 7 is a side view of the power storage device. Fig. 8 is an enlarged perspective view of a region of the electrode body holder including the notch portion. Fig. 6 and 7 show a state in which the inside of the power storage device is seen through. In fig. 6 to 8, the electrode body is schematically illustrated.

The power storage device 1 includes a case 2, a pair of output terminals 4, an electrode body 6, a pair of current collecting portions 8, and an electrode body holder 10. The displacement of the electrode body 6 inside the case 2 is restricted by the electrode body holder 10. The electrode body holder 10 is in contact with a pair of first surfaces 6a of the electrode body 6 facing in the 1 st direction X in which the pair of current collecting portions 8 are arranged. The electrode body holder 10 is fixed to the case 2 and sandwiches the electrode body 6 in the 1 st direction X. This can suppress displacement of the electrode body 6. In particular, displacement of the electrode body 6 in the 1 st direction X can be suppressed.

The electrode body holder 10 has a 2 nd plate portion 28 and a pair of 1 st plate portions 26. The 1 st plate portion 26 and the 2 nd plate portion 28 of the present embodiment are integrally molded resin. The pair of 1 st plate portions 26 extend in the 3 rd direction Z and abut against the pair of 1 st surfaces 6 a. Each of the 1 st plate portions 26 is separated from the short side surfaces of the case 2. The 2 nd plate portion 28 is formed integrally with each 1 st plate portion 26, is interposed between the sealing plate 14 (terminal arrangement portion) and the electrode body 6, and is fixed to the sealing plate 14.

The 2 nd plate portion 28 of the present embodiment has an engaging convex portion 44 protruding toward the sealing plate 14. For example, two engaging protrusions 44 are arranged at both ends of the sealing plate 14 in the 1 st direction X so as to be aligned in the 2 nd direction Y. Further, the sealing plate 14 has through holes 46 at positions overlapping the respective engaging protrusions 44 when viewed in the 3 rd direction Z. The through-hole 46 is penetrated by each engaging protrusion 44. Thereby, the 2 nd plate portion 28 is fixed to the sealing plate 14. For example, the 2 nd plate portion 28 is press-fitted and fixed to the sealing plate 14.

In the present embodiment, the thickness T2 of the 2 nd plate portion 28 is larger than the thickness T1 of the 1 st plate portion 26. The thickness T2 of the 2 nd plate portion 28 is the size of the 2 rd plate portion 28 in the 3 rd direction Z. The thickness T1 of the 1 st plate portion 26 is the size of the 1 st plate portion 26 in the 1 st direction X. The thickness T2 is larger than the distance from the lower surface of the sealing plate 14 to the lower end of the portion of the current collector laminate bonded to the current collector plate 22. This makes it possible to easily suppress displacement of the electrode body 6 in the direction approaching the sealing plate 14, that is, displacement in the 3 rd direction Z, by the electrode body holder 10. The 2 nd plate portion 28 of the present embodiment is in contact with the sealing plate 14 (terminal arrangement portion) and the electrode body 6. This makes it possible to more reliably suppress the displacement of the electrode body 6 in the 3 rd direction Z by the electrode body holder 10. As a result, the load applied to the current collecting tab 24 can be further reduced.

The electrode body holder 10 is composed of a pair of holder units 10a and 10b arranged in the 1 st direction X. The pair of holder units 10a, 10b have the 1 st plate portion 26 and the 2 nd plate portion 28, respectively. Further, each of the 2 nd plate portions 28 has an engaging convex portion 44. One holder unit 10a is pressed and fixed to sealing plate 14 in contact with one 1 st surface 6a of electrode body 6. The other holder unit 10b is pressed and fixed to the sealing plate 14 in contact with the other 1 st surface 6a of the electrode body 6. The method of fixing electrode body holder 10 to sealing plate 14 is not limited to press-fitting.

The electrode body holder 10 has a notch 48 in a region facing the electrode body 6 of the connection portion 32 between the 1 st plate 26 and the 2 nd plate 28. The notch 48 is a recess provided at a corner portion inside the connecting portion 32 between the 1 st plate 26 and the 2 nd plate 28 and bent in a direction away from the electrode body 6. Thus, the 1 st plate portion 26 and the 2 nd plate portion 28 are smoothly coupled at the connecting portion 32. By providing the notch 48, when the 1 st plate 26 is pressed in the outer direction of the power storage device 1 due to displacement of the electrode body 6 in the 1 st direction X, stress concentration at the inner corner of the connecting portion 32 can be suppressed. This can prevent breakage of the electrode body holder 10, and can suppress displacement of the electrode body 6 more stably. Further, stress concentration on the corner portions of the electrode body 6 can be suppressed. This can suppress breakage of the electrode assembly 6.

Power storage device 1 of the present embodiment includes a pair of insulating members 50 for insulating sealing plate 14 and current collecting plate 22 (see fig. 2). That is, in the present embodiment, the 2 nd plate portion 28 and the insulating member 50 are separate members. Each insulating member 50 is fixed to the sealing plate 14 via each output terminal 4, and is interposed between the current collecting plate 22 and the sealing plate 14 to electrically insulate them.

The embodiments of the power storage device of the present disclosure are described above in detail. The above-described embodiments merely show specific examples when the power storage device of the present disclosure is implemented. The contents of the embodiments do not limit the protective scope of the power storage device of the present disclosure, and various design changes such as changes, additions, and deletions of the components can be made without departing from the scope of the inventive concept defined in the claims. The new embodiment to which the design change is added has both the effects of the combined embodiment and the modification. In the above-described embodiments, the contents that can be subjected to such design changes are emphasized with expressions such as "in the present embodiment" and "in the present embodiment", but even contents that do not have such expressions allow design changes. The hatching marked on the cross section of the drawing does not limit the material of the object marked with hatching.

(modification 1)

Fig. 9 (a) is a perspective view of power storage device 1 according to modification 1. Fig. 9 (B) is a perspective view of the 2 nd electrode body holder. In fig. 9 (a), the outer can 12 is not shown. The power storage device 1 of modification 1 includes an electrode body holder other than the electrode body holder 10, in addition to the electrode body holder 10 included in the power storage device 1 of embodiment 1 or 2. In the following description, for convenience of explanation, the electrode body holder 10 according to embodiment 1 or 2 is referred to as a 1 st electrode body holder 10X, and the electrode body holders other than the 1 st electrode body holder 10X are referred to as a 2 nd electrode body holder 10Y. In fig. 9 (a), the electrode body holder 10 of embodiment 1 is illustrated as a 1 st electrode body holder 10X.

The electrode body 6 has a 2 nd surface 6b connecting end portions of the pair of 1 st surfaces 6a on the opposite side to the terminal arrangement portion to each other. The 2 nd surface 6b is a bottom surface of the electrode body 6. The 2 nd electrode body holder 10Y has a 4 th plate portion 54 and a pair of 3 rd plate portions 52. The pair of 3 rd plate portions 52 extend in the 3 rd direction Z and abut on the pair of 1 st surfaces 6 a. Specifically, the one 3 rd plate portion 52 abuts on the 1 st surface 6a on the positive electrode terminal 4a side at a position below the 1 st plate portion 26 of the 1 st electrode body holder 10X. The other 3 rd plate portion 52 is in contact with the 1 st surface 6a on the negative electrode terminal 4b side at a position below the 1 st plate portion 26 of the 1 st electrode body holder 10X.

The 4 th plate portion 54 extends in the 1 st direction X and contacts the 2 nd surface 6b of the electrode body 6, and both end portions are connected to the pair of 3 rd plate portions 52. Therefore, the 2 nd electrode body holder 10Y has a substantially U shape when viewed from the 2 nd direction Y. By attaching the 2 nd electrode body holder 10Y to the electrode body 6, displacement of the electrode body 6 can be further suppressed. This can further improve the reliability of power storage device 1. Further, in the power storage device of the present disclosure, the 2 nd electrode body holder 10Y is not essential.

(others)

The electrode body 6 is not limited to a laminated electrode body in which a plurality of positive electrode plates and a plurality of negative electrode plates are alternately laminated with a plate separator interposed therebetween. For example, the electrode body 6 may be a flat wound electrode body in which a strip-shaped positive electrode plate and a strip-shaped negative electrode plate are stacked with a plate separator interposed therebetween, and the electrode body is wound and compressed in a predetermined direction. The shape of the opening 12a of the outer can 12 may be a square shape such as a square, a polygonal shape other than a quadrangle, or the like. The terminal arrangement portion may be provided in the outer can 12. The output terminals 4 may not be arranged in the 1 st direction X.

Description of the reference numerals

1. An electrical storage device; 2. a housing; 4. an output terminal; 6. an electrode body; 6a, the 1 st surface; 6b, the 2 nd surface; 8. a current collecting part; 10. an electrode body holder; 10a, 10b, a holder unit; 10X, 1 st electrode body holder; 10Y, the 2 nd electrode body holder; 22. a collector plate; 24. a current collecting plate; 26. a 1 st plate portion; 28. a 2 nd plate portion; 32. a connecting portion; 48. a notch portion; 52. a 3 rd plate portion; 54. a 4 th plate portion.