Power storage device

Abstract

To provide a structure where bonding between power storage bodies and a case is hardly removed.SOLUTION: A power storage device 1 comprises a plurality of power storage bodies 10, and a housing case 20. The plurality of power storage bodies 10 are aligned in an X-direction and are stacked in the X-direction. A lower surface 12 of each of the power storage bodies 10 is bonded to a lower case 22 by bonding materials 30 and 30a. An upper case 21 has a protruding part P which extends in the X-direction. The protruding part P protrudes in the direction of the lower case 22 and comes into contact with an upper surface 11 of each of the power storage bodies 10. As a result, each of the power storage bodies 10 receives a load on the bonding materials 30 and 30a side (the lower case 22 side) so as to be pressed down.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present disclosure relates to an electricity storage device. [Background technology]

[0002] Japanese Patent Application Laid-Open No. 2023-46013 (Patent Document 1) discloses a battery pack in which a plurality of battery cells and the bottom of the case are bonded together using an adhesive heat transfer member. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2023-46013 Summary of the Invention [Problem to be solved by the invention]

[0004] If the battery pack is subjected to vibrations or other forces, there is a concern that the adhesive between the battery cell (electrical storage unit) and the case may come off.

[0005] An object of the present disclosure is to provide a structure in which the adhesion between the power storage unit and the case is less likely to separate. [Means for solving the problem]

[0006] The power storage device according to the present disclosure is a power storage device including a plurality of power storage units and a housing case including a first case and a second case, and housing the plurality of power storage units in a space formed by the first case and the second case. The plurality of power storage units are bonded to the first case, and the second case has a protruding portion that protrudes toward the first case, and the protruding portion abuts against the power storage units.

[0007] With this configuration, the multiple power storage units are bonded to the first case. The protruding portions of the second case protrude toward the first case and abut against the power storage units. The power storage units are pressed toward the first case by the protruding portions of the second case, which prevents the power storage units from being separated from the housing case.

[0008] Preferably, the plurality of power storage units are arranged in a stacking direction in the casing, and the protrusion may extend in the stacking direction.

[0009] According to this configuration, the protruding portion of the second case can press the plurality of power storage units toward the first case.

[0010] Each of the plurality of power storage units may be a rectangular parallelepiped, and may be bonded to the first case at the center of the long side of the power storage unit, and the protrusion may abut the power storage unit at the center of the long side of the power storage unit.

[0011] According to this configuration, the center of the power storage unit can be adhered to the storage case. Each of the plurality of power storage bodies may include a cell assembly in which a plurality of power storage cells arranged in the connection direction are electrically connected at connection parts, a cell case that houses the cell assembly, and a reinforcing member that is disposed at the connection part and reinforces the cell case. In this case, the protrusion of the second case may abut against the cell case at a position where the reinforcing member is disposed.

[0012] According to this configuration, the protrusion abuts against the cell case at the position where the reinforcing member is arranged, so that the electricity storage unit can be suitably pressed against the first case side.

[0013] Furthermore, the cell case may be bonded to the first case at the location where the reinforcing member is disposed.

[0014] According to this configuration, the cell case is adhered to the first case at the position where the reinforcing member is arranged, so that the force applied to the storage battery by the protrusion of the second case is suitably transmitted to the adhesive point through the reinforcing member. [Effects of the Invention]

[0015] According to the present disclosure, a structure can be provided in which the adhesion between the power storage unit and the case is less likely to separate. [Brief explanation of the drawings]

[0016] [Figure 1] 1 is a perspective view schematically showing an electricity storage device according to an embodiment of the present invention; [Figure 2] 1 is a diagram schematically illustrating an example of a power storage unit 10. FIG. [Figure 3] 3A and 3B are cross-sectional views taken along the line III-III in FIG. [Figure 4] FIG. 10 is an exploded perspective view of a power storage unit according to a second embodiment. [Figure 5] FIG. 10 is a cross-sectional view of an electricity storage device according to a second embodiment. [Figure 6] FIG. 10 is a perspective view that schematically shows a power storage device 1B in a modified example. DETAILED DESCRIPTION OF THE INVENTION

[0017] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. In the drawings, identical or corresponding parts are designated by the same reference numerals, and their description will not be repeated. The drawings are not drawn according to the actual dimensional ratio, and in some cases, the ratio is changed to clarify the structure in order to facilitate understanding of the structure. The embodiments and modifications described below may be combined as appropriate and selectively.

[0018] [Embodiment 1] The electricity storage device according to the present embodiment will be described with reference to Figures 1 to 3. Figure 1 is a perspective view that schematically shows the electricity storage device according to the present embodiment.

[0019] 1, a power storage device 1 is mounted on a vehicle for use, for example. Examples of the vehicle include a hybrid vehicle, a plug-in hybrid vehicle, a fuel cell vehicle, and an electric vehicle. The power storage device 1 includes a plurality of power storage units 10 and a housing case 20 that houses the plurality of power storage units 10.

[0020] The power storage unit 10 is a secondary battery, typically a lithium-ion battery. A lithium-ion battery is a battery that uses lithium as a charge carrier, and may include not only common lithium-ion secondary batteries that use a liquid electrolyte, but also so-called all-solid-state batteries that use a solid electrolyte. Examples of lithium-ion batteries include LFP batteries that use lithium iron phosphate as the positive electrode active material, and ternary batteries that use NMC (nickel-manganese-cobalt) as the positive electrode active material. Note that the power storage unit 10 is not limited to a lithium-ion secondary battery, and may be composed of a nickel-metal hydride secondary battery or other secondary batteries.

[0021] 2 is a diagram schematically illustrating an example of a power storage unit 10. In this embodiment, the power storage unit 10 is a stacked lithium-ion battery in which a plurality of battery cells are stacked in a cell case, each battery cell being formed by stacking a positive electrode sheet (current collector) coated with a positive electrode active material and a negative electrode sheet (current collector) coated with a negative electrode active material, with a separator interposed therebetween. Note that the power storage unit 10 may also be a bipolar lithium-ion battery in which a positive electrode active material is coated on one side of a current collector and a negative electrode active material is coated on the other side of the current collector, and the cells are stacked with a separator interposed therebetween.

[0022] Referring to FIG. 2, the power storage unit 10 is a rectangular parallelepiped and includes an upper surface 11, a lower surface 12, a pair of short side surfaces 13 and 14, and a pair of long side surfaces 15 and 16, with the long sides (longest sides) extending in the Y direction. The power storage unit 10 further includes a positive electrode terminal 17 and a negative electrode terminal 18. The positive electrode terminal 17 is provided on one of the pair of short side surfaces 13 and 14, and the negative electrode terminal 18 is provided on the other of the pair of short side surfaces 13 and 14. In the example shown in FIG. 2, the positive electrode terminal 17 is provided on the short side surface 14, and the negative electrode terminal 18 is provided on the short side surface 13. Note that both the positive electrode terminal 17 and the negative electrode terminal 18 may be provided on one of the pair of short side surfaces 13 and 14.

[0023] Referring to FIG. 1, the storage case 20 includes an upper case 21 and a lower case 22. The lower case 22 includes a bottom plate and a peripheral wall. The bottom plate is formed in a flat plate shape. The peripheral wall is formed to extend upward from the outer peripheral edge of the bottom plate, and is formed in an annular shape. The multiple power storage units 10 are housed in a space formed by assembling the upper case 21 to the lower case 22. FIG. 1 shows the power storage device 1 with the upper case 21 removed. The upper case 21 corresponds to an example of a "second case" in the present disclosure, and the lower case 22 corresponds to an example of a "first case" in the present disclosure.

[0024] The power storage units 10 are arranged and stacked in the X direction in the space formed by the upper case 21 and the lower case 22, and are thereby housed in the housing case 20. In this embodiment, the X direction corresponds to the "stacking direction" of the present disclosure.

[0025] Fig. 3 is a cross-sectional view taken along the line III-III in Fig. 1. Fig. 3(A) shows an example in which the central portion of the long side of the power storage unit 10 is bonded, and Fig. 3(B) shows an example in which the entire power storage unit 10 is bonded.

[0026] 3(A), the bottom surface 12 of the power storage unit 10 and the lower case 22 are bonded together with an adhesive 30 at approximately the center of the long side of the power storage unit 10. The upper case 21 is formed with a protrusion P extending in the X direction (stacking direction). The protrusion P protrudes toward the lower case 22. The protrusion P abuts against the top surface 11 of the power storage unit 10 at approximately the center of the long side of the power storage unit 10. The adhesive 30 and the protrusion P are positioned so as to overlap in the Z direction.

[0027] 3(B), the lower surface 12 of the power storage unit 10 and the lower case 22 are bonded together with an adhesive 30a. The adhesive 30a bonds almost the entire lower surface 12 of the power storage unit 10 to the lower case 22. The upper case 21 is formed with a protrusion P extending in the X direction (stacking direction). The protrusion P protrudes toward the lower case 22. The protrusion P abuts against the upper surface 11 of the power storage unit 10 at approximately the center of the power storage unit 10 in the long side direction.

[0028] 3(A) and 3(B), the protrusion P of the upper case 21 abuts against the top surface 11 of the power storage unit 10, so that the power storage unit 10 receives a load on the adhesives 30, 30a side (lower case 22 side) and is pressed down. This makes it possible to prevent the adhesion between the power storage unit 10 and the accommodating case 20 (lower case 22) from peeling off. Furthermore, in the configuration of FIG. 3(A), the adhesive 30 and the protrusion P are positioned so as to overlap in the Z direction, so that even when the center of the long side of the power storage unit 10 is adhered to the lower case 22, it is possible to suitably prevent the adhesion between the power storage unit 10 and the accommodating case 20 (lower case 22) from peeling off.

[0029] 3(A) and 3(B), a cooler for cooling the power storage unit 10 may be disposed in the space between the upper case 21 and the top surface 11 of the power storage unit 10. In the configuration of Fig. 3(A), a cooler may be disposed between the bottom surface 12 of the power storage unit 10 and the lower case 22 on both sides of the adhesive 30 in the Y direction.

[0030] [Embodiment 2] 4 is an exploded perspective view of a power storage unit 10A according to the second embodiment. In the second embodiment, the power storage unit 10A includes a cell assembly 50 in which a plurality of power storage cells 100 are electrically connected at connection portions 110. The power storage cell 100 is, for example, a lithium ion battery. The power storage cell 100 is composed of, for example, an electrode assembly including a wound assembly in which a positive electrode sheet coated with a positive electrode active material and a negative electrode sheet coated with a negative electrode active material are wound with a separator interposed therebetween, and a laminate exterior body 160 that seals the electrode assembly.

[0031] The energy storage cells 100 are provided with current collecting terminals 140 (one positive electrode, the other negative electrode) at both ends in the Y direction, and the current collecting terminals 140 of adjacent energy storage cells 100 are electrically connected in series at connection portions 110 to form a cell assembly 50. The cell assembly 50 is inserted into a cell case 300, and a cover member 310 is joined to the cell case 300, whereby the cell assembly 50 is housed in the cell case 300, and an energy storage unit 10A is formed. FIG. 4 shows a perspective view of the cell assembly 50 when being inserted into the cell case 300. The energy storage unit 10A is composed of the cell assembly 50, in which a plurality of energy storage cells 100 arranged in the Y direction (connecting direction) are electrically connected, and the cell case 300 that houses the cell assembly 50.

[0032] A pair of reinforcing members 200 are provided at the connection portion 110 of the cell connected body 50 so as to sandwich the current collecting terminal 140. The reinforcing members 200 are in the shape of a rectangular prism that is hollow in the Z direction. The material of the reinforcing members 200 may be synthetic resin or metal. The length of the reinforcing members 200 in the Z direction is the same as the width of the inner surface of the cell casing 300 in the Z direction. As a result, the reinforcing members 200 function as reinforcing members (so-called support rods) for the cell casing 300 at the connection portion 110 of the cell connected body 50.

[0033] Output terminals 400 (one is a positive terminal and the other is a negative terminal) are connected to the current collecting terminals 140 on both sides of the cell connected body 50. In addition, a pair of reinforcing members 210 similar to the reinforcing member 200 may be provided to sandwich the current collecting terminals 140 on both sides of the cell connected body 50.

[0034] Fig. 5 is a cross-sectional view of a power storage device 1A according to embodiment 2. This cross-sectional view is a cross-sectional view of a portion similar to that of Fig. 3. In embodiment 2, a cell connected body 50 is configured of three power storage cells 100. The storage case 20A includes an upper case 21A and a lower case 22A. The multiple power storage units 10A are arranged in the X direction in a space formed by the upper case 21A and the lower case 22A and stacked, thereby being housed in the storage case 20A.

[0035] The lower surface 12A of the power storage unit 10A (cell case 300) and the lower case 22A are bonded together with adhesive materials 30A, 30A. The adhesive material 30A is provided at the position where the reinforcing member 200 is arranged (the position of the connection portion 110 of the cell connected body 50), and bonds the power storage unit 10A and the lower case 22A together. The upper case 21 is formed with protrusions P1, P2 extending in the X direction (stacking direction). The protrusions P1, P2 protrude toward the lower case 22A. The protrusions P1, P2 abut against the upper surface 11A of the power storage unit 10A (cell case 300). The adhesive materials 30A, 30A and the protrusions P1, P2 are positioned to overlap in the Z direction.

[0036] According to the second embodiment, the protrusions P1 and P2 of the upper case 21A contact the top surface 11A of the power storage unit 10A (cell case 300), and the power storage unit 10A is pressed down by the adhesive 30A (on the lower case 22A side). This prevents the power storage unit 10A from being separated from the casing 20A (lower case 22A). Furthermore, the protrusions P and P2 and the adhesives 30A are arranged in positions where they overlap in the Z direction at the position where the reinforcing member 200 is arranged. This allows the force applied to the power storage unit 10A (cell case 300) by the protrusions P1 and P2 to be efficiently transmitted to the adhesives 30A (bonding locations) through the reinforcing member 200, more preferably preventing the power storage unit 10A from being separated from the casing 20A (lower case 22A).

[0037] In the second embodiment, the cell connected body 50 is configured from three energy storage cells 100, but the number of energy storage cells 100 may be two, or four or more.

[0038] [Variations] FIG. 6 is a perspective view schematically showing a power storage device 1B according to the modified example. In the power storage device 1B according to the modified example, a plurality of partition walls 61, 62, and 63 are formed in a lower case 22B of a storage case 20B. The partition walls 61 and 62 are formed to extend in the X direction, and the partition wall 63 is formed in the center of the lower case 22B in the X direction to extend in the Y direction. The plurality of power accumulators 10 have the same configuration as in the first embodiment. The power accumulators 10 are arranged and stacked in the Y direction between the partition walls 61 and 62 and are housed in the storage case 20B. The power accumulators 10 are also arranged in two rows by being partitioned by the partition wall 63.

[0039] Each power storage unit 10 is adhered to the bottom surface of the lower case 22B with an adhesive. Protrusions P3 and P4 extending in the Y direction (stacking direction) are formed on the upper case 22B. The protrusions P3 and P4 protrude toward the lower case 22B. The protrusions P3 and P4 abut against the power storage unit 10 at approximately the center of the power storage unit 10 in the long side direction.

[0040] In this modification as well, protrusions P3 and P4 of upper case 21B come into contact with power storage unit 10, so that power storage unit 10 is pressed down by a load on the adhesive side (lower case 22B side). This makes it possible to prevent separation of the adhesion between power storage unit 10 and accommodating case 20B (lower case 22B).

[0041] In the above embodiment, some of the power storage units (for example, power storage units at the ends in the stacking direction) may not be in contact with the protrusions formed on the upper case.

[0042] The embodiments disclosed herein should be considered to be illustrative in all respects and not restrictive. The scope of the present disclosure is defined by the claims, not by the above description, and is intended to include all modifications within the meaning and scope of the claims. [Explanation of symbols]

[0043] 1, 1A, 1B Electricity storage device, 10, 10A Electricity storage body, 11, 11A Upper surface, 12, 12A Lower surface, 20, 20A, 20B Storage case, 21, 21A, 21B Upper case, 22, 22A, 22B Lower case, 30, 30a, 30A Adhesive, 50 Cell connecting body, 100 Electricity storage cell, 110 Connection part, 200 Reinforcing member, 300 Cell case

Claims

1. A plurality of power storage units; a storage case including a first case and a second case, the storage case storing the plurality of power storage units in a space formed by the first case and the second case, the plurality of power storage units are bonded to the first case, the second case has a protrusion that protrudes toward the first case, The protrusion is in contact with the power storage unit.

2. the plurality of power storage units are arranged in the housing case in a stacking direction, The power storage device according to claim 1 , wherein the protrusion extends in the stacking direction.

3. Each of the plurality of power storage units is a rectangular parallelepiped, the power storage unit is bonded to the first case at a center portion in a long side direction, The power storage device according to claim 1 or 2, wherein the protrusion abuts against the power storage body at a center portion in the long side direction.

4. Each of the plurality of power storage units is a cell connection body in which a plurality of storage cells arranged in a connection direction are electrically connected at connection portions; a cell case that accommodates the cell assembly; a reinforcing member disposed at the connection portion for reinforcing the cell case, The power storage device according to claim 1 or 2, wherein the protrusion abuts against the cell case at a position where the reinforcing member is disposed.

5. The power storage device according to claim 4 , wherein the cell case is bonded to the first case at a position where the reinforcing member is disposed.

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