Electricity storage device

Abstract

The invention relates to a power storage device. The power storage device includes a plurality of power storage bodies and a housing case. The plurality of power storage bodies are arranged in the X direction and stacked in the X direction. And the lower surface of the power storage body is bonded with the lower shell through a bonding piece. A protruding portion extending in the X direction is formed on the upper case. The protruding portion protrudes toward the lower case and comes into contact with the upper surface of the electricity storage body. As a result, the power storage body is pressed by receiving a load on the adhesive material side (lower case side).

Description

Technical Field

[0001] The present disclosure relates to a power storage device. Background Art

[0002] Japanese Patent Application Laid-Open No. 2023-46013 discloses a battery pack in which a plurality of battery cells are bonded to the bottom of a case using a heat-conductive member having adhesive properties.

[0003] If vibration or the like is applied to the battery pack, there is a possibility that the adhesion between the battery cell (electricity storage body) and the outer casing may be peeled off. Summary of the Invention

[0004] An object of the present disclosure is to provide a structure in which the adhesion between a power storage body and a casing is unlikely to be peeled off.

[0005] The power storage device disclosed herein comprises a plurality of power storage elements and a housing. The housing comprises a first housing and a second housing, and the plurality of power storage elements are housed within a space defined by the first and second housings. The plurality of power storage elements are bonded to the first housing, and the second housing has a protrusion that protrudes toward the first housing, and the protrusion abuts against the power storage elements.

[0006] With this configuration, multiple power storage elements are bonded to the first outer case. The protrusion of the second outer case protrudes toward the first outer case and abuts against the power storage elements. Because the power storage elements are pressed toward the first outer case by the protrusion of the second outer case, any separation of the bond between the power storage elements and the housing case can be suppressed.

[0007] Preferably, the plurality of electricity storage bodies are arranged in the housing case along a stacking direction, and the protrusion extends along the stacking direction.

[0008] According to this configuration, the plurality of electricity storage bodies can be pressed toward the first case by the protruding portion of the second case.

[0009] Each of the plurality of electricity storage bodies may be a rectangular parallelepiped and bonded to the first case at a center portion in the longitudinal direction of the electricity storage body, and the protrusion may abut against the electricity storage body at a center portion in the longitudinal direction of the electricity storage body.

[0010] According to this configuration, the central portion of the electricity storage body and the housing case can be bonded together.

[0011] Each of the plurality of power storage units may include a cell connector that electrically connects a plurality of power storage cells arranged along a connection direction at a connection portion; a cell case that houses the cell connector; and a reinforcing member disposed at the connection portion and configured to reinforce the cell case. In this case, the protrusion of the second case may abut the cell case at the location where the reinforcing member is disposed.

[0012] According to this configuration, since the protrusion abuts against the cell case at the position where the reinforcing member is arranged, the electric power storage body can be pressed toward the first case in a favorable manner.

[0013] Furthermore, the cell case may be bonded to the first case at a position where the reinforcing member is arranged.

[0014] According to this configuration, since the cell case is bonded to the first case at the position where the reinforcing member is arranged, the force applied to the electricity storage body by the protrusion of the second case is well transmitted to the bonded portion via the reinforcing member.

[0015] According to the present disclosure, it is possible to provide a structure in which the bond between the electricity storage body and the outer case is unlikely to be peeled off. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Features, advantages, and technical and industrial significance of exemplary embodiments of the present invention are described below with reference to the accompanying drawings, in which like reference numerals represent like elements, wherein:

[0017] Figure 1 It is a perspective view schematically showing the power storage device according to this embodiment.

[0018] Figure 2 It is a diagram schematically showing an example of the electricity storage body 10 .

[0019] Figure 3A yes Figure 1 Sectional view III-III.

[0020] Figure 3B yes Figure 1 Sectional view III-III.

[0021] Figure 4 This is an exploded perspective view of the electricity storage body according to the second embodiment.

[0022] Figure 5 This is a cross-sectional view of the power storage device according to the second embodiment.

[0023] Figure 6 It is a perspective view schematically showing an electric storage device 1B according to a modification. DETAILED DESCRIPTION

[0024] The following describes the embodiments of the present disclosure in detail with reference to the accompanying drawings. In the accompanying drawings, identical or equivalent parts are denoted by the same reference numerals, and their descriptions are not repeated. In the accompanying drawings, the figures are not drawn according to the ratios of actual dimensions. To facilitate understanding of the structure, the figures may be drawn with the ratios changed so that the structure becomes clearer. The embodiments and modifications described below may also be selectively combined as appropriate.

[0025] [Implementation Method 1]

[0026] Reference Figures 1 to 3B , the power storage device involved in this embodiment is described. Figure 1 It is a perspective view schematically showing the power storage device according to this embodiment.

[0027] Reference Figure 1 The power storage device 1 is used, for example, by being mounted on a vehicle. Examples of vehicles include hybrid vehicles, plug-in hybrid vehicles, fuel cell vehicles, and electric vehicles. The power storage device 1 includes a plurality of power storage elements 10 and a housing case 20 that houses the plurality of power storage elements 10.

[0028] The power storage body 10 is a secondary battery, typically a lithium-ion battery. A lithium-ion battery is a battery that uses lithium as a charge carrier. In addition to general lithium-ion secondary batteries with liquid electrolytes, it also includes so-called all-solid-state batteries that use solid electrolytes. Examples of lithium-ion batteries include LFP batteries that use lithium iron phosphate as the positive electrode active material, or ternary batteries that use NMC (nickel manganese cobalt) as the positive electrode active material. In addition, the power storage body 10 is not limited to lithium-ion secondary batteries, and can also be composed of nickel-metal hydride secondary batteries or other secondary batteries.

[0029] Figure 2 This figure schematically illustrates an example of a power storage unit 10. In this embodiment, power storage unit 10 is a stacked lithium-ion battery comprising a plurality of battery cells stacked within a cell housing. These battery cells are 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. Alternatively, a bipolar lithium-ion battery may be employed, in which a positive electrode active material is coated on one side of the current collector and a negative electrode active material is coated on the other side, with the layers stacked with a separator interposed therebetween.

[0030] Reference Figure 2 The battery 10 is a rectangular parallelepiped, including an upper surface 11, a lower surface 12, a pair of short side surfaces 13, 14, and a pair of long side surfaces 15, 16, with the long side (the longest side) extending along the Y direction. The battery 10 also includes a positive terminal 17 and a negative terminal 18. The positive terminal 17 is provided on one of the pair of short side surfaces 13, 14, and the negative terminal 18 is provided on the other of the pair of short side surfaces 13, 14. Figure 2 In the example shown, 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. Alternatively, 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.

[0031] Reference Figure 1The housing 20 includes an upper shell 21 and a lower shell 22. The lower shell 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 the peripheral wall is formed in a ring shape. A plurality of storage bodies 10 are stored in the space formed by assembling the upper shell 21 to the lower shell 22. Figure 1 2 shows the power storage device 1 in a state where the upper case 21 is removed. The upper case 21 corresponds to an example of the “second case” of the present disclosure, and the lower case 22 corresponds to an example of the “first case” of the present disclosure.

[0032] The electricity storage bodies 10 are arranged along the X direction and stacked in a space formed by the upper case 21 and the lower case 22, thereby being housed in the housing case 20. In the present embodiment, the X direction corresponds to the "stacking direction" of the present disclosure.

[0033] Figure 3A 、 Figure 3B yes Figure 1 Sectional view III-III. Figure 3A This is an example of bonding the central portion of the long side direction of the electricity storage body 10. Figure 3B This is an example in which the entire electricity storage body 10 is bonded.

[0034] Reference Figure 3A The lower surface 12 of the electricity storage body 10 and the lower shell 22 are bonded together by an adhesive 30 at approximately the center of the longitudinal direction of the electricity storage body 10. A protrusion P extending in the X direction (the stacking direction) is formed on the upper shell 21. The protrusion P protrudes toward the lower shell 22. The protrusion P abuts against the upper surface 11 of the electricity storage body 10 at approximately the center of the longitudinal direction of the electricity storage body 10. The adhesive 30 and the protrusion P are arranged so that they overlap in the Z direction.

[0035] Reference Figure 3B The lower surface 12 of the electricity storage body 10 and the lower shell 22 are bonded together by an adhesive 30a. The adhesive 30a bonds substantially the entire lower surface 12 of the electricity storage body 10 to the lower shell 22. A protrusion P extending in the X direction (the stacking direction) is formed on the upper shell 21. The protrusion P protrudes toward the lower shell 22. The protrusion P abuts against the upper surface 11 of the electricity storage body 10 at approximately the center of the longitudinal direction of the electricity storage body 10.

[0036] according to Figure 3A 、 Figure 3B The structure is such that the protrusion P of the upper shell 21 contacts the upper surface 11 of the storage body 10, thereby the storage body 10 receives a load on the adhesive member 30, 30a side (lower shell 22 side) and is pressed. This can prevent the storage body 10 from being peeled off from the storage case 20 (lower shell 22). In addition, Figure 3AIn the structure, since the adhesive member 30 and the protrusion P are arranged at overlapping positions in the Z direction, even when the central part of the long side direction of the storage body 10 is adhered to the lower shell 22, the adhesion and peeling between the storage body 10 and the storage shell 20 (lower shell 22) can be well suppressed.

[0037] In addition, Figure 3A 、 Figure 3B In the structure, a cooler for cooling the electricity storage body 10 may be arranged in the space between the upper shell 21 and the upper surface 11 of the electricity storage body 10. Figure 3A In the structure, a cooler may be arranged between the lower surface 12 of the electricity storage body 10 and the lower case 22 on both sides of the adhesive member 30 in the Y direction.

[0038] [Implementation Method 2]

[0039] Figure 4 This is an exploded perspective view of a power storage unit 10A according to Embodiment 2. In Embodiment 2, power storage unit 10A includes a cell connector 50 that electrically connects a plurality of power storage cells 100 at connectors 110. Power storage cells 100 are, for example, lithium-ion batteries. Power storage cells 100 are composed of, for example, an electrode assembly comprising a wound body formed by winding a positive electrode sheet coated with a positive active material and a negative electrode sheet coated with a negative active material, with a separator interposed therebetween, and a laminated exterior body 160 that seals the electrode assembly.

[0040] The storage cells 100 have current collector terminals 140 (one is a positive electrode, the other is a negative electrode) at both ends in the Y direction. The current collector terminals 140 of adjacent storage cells 100 are electrically connected in series at the connection portion 110, thereby forming a cell connection body 50. The cell connection body 50 is inserted into the cell case 300 and the lid member 310 is joined to the cell case 300. The cell connection body 50 is housed in the cell case 300, thereby forming the storage body 10A. Figure 4 The figure shows a perspective view of the cell connecting body 50 inserted into the cell case 300. The power storage body 10A is composed of the cell connecting body 50 electrically connecting a plurality of power storage cells 100 arranged in the Y direction (connection direction), and the cell case 300 housing the cell connecting body 50.

[0041] A pair of reinforcing members 200 are provided at the connection portion 110 of the cell connector 50 so as to sandwich the current collector terminal 140. The reinforcing members 200 are in the shape of a quadrangular prism that is hollow in the Z direction. The reinforcing members 200 can be made of either 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. Thus, 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 connector 50.

[0042] Output terminals 400 (one is a positive terminal, the other is a negative terminal) are connected to the current collector terminals 140 on both sides of the cell connector 50. Alternatively, a pair of reinforcing members 210 similar to the reinforcing member 200 may be provided to sandwich the current collector terminals 140 on both sides of the cell connector 50.

[0043] Figure 5 This is a cross-sectional view of the power storage device 1A according to the second embodiment. Figure 3A 、 Figure 3B Cross-sectional view of the same portion. In the second embodiment, the cell connection assembly 50 is formed by three storage cells 100. The storage case 20A includes an upper case 21A and a lower case 22A. The multiple storage cells 10A are arranged and stacked along the X direction in the space formed by the upper case 21A and the lower case 22A, thereby being housed in the storage case 20A.

[0044] The lower surface 12A of the battery cell 10A (battery cell casing 300) and the lower shell 22A are bonded together by adhesives 30A, 30A. The adhesive 30A is provided at a position where the reinforcing member 200 is provided (the position of the connection portion 110 of the battery cell connector 50), and bonds the battery cell 10A and the lower shell 22A together. Protrusions P1, P2 extending in the X direction (stacking direction) are formed on the upper shell 21. The protrusions P1, P2 protrude toward the lower shell 22A. The protrusions P1, P2 abut against the upper surface 11A of the battery cell 10A (battery cell casing 300). The adhesives 30A, 30A and the protrusions P1, P2 are arranged so as to overlap in the Z direction.

[0045] According to this second embodiment, the protrusions P1 and P2 of the upper shell 21A abut against the upper surface 11A of the battery cell 10A (battery cell casing 300), so that the battery cell 10A is subjected to a load and pressed by the adhesive member 30A (lower shell 22A side). As a result, it is possible to suppress the adhesive peeling between the battery cell 10A and the storage casing 20A (lower shell 22A). In addition, the protrusions P1 and P2 and the adhesive members 30A and 30A are arranged at positions where they overlap in the Z direction at the position where the reinforcing member 200 is arranged. As a result, the force applied to the battery cell 10A (battery cell casing 300) by the protrusions P1 and P2 is efficiently transmitted to the adhesive members 30A and 30A (adhesive portion) through the reinforcing member 200, which can better suppress the adhesive peeling between the battery cell 10A and the storage casing 20A (lower shell 22A).

[0046] Furthermore, in the second embodiment, the cell connection body 50 is composed of three storage cells 100 , but the number of storage cells 100 may be two or four or more.

[0047] [Modification]

[0048] Figure 6 This is a perspective view schematically showing a modified example of an energy storage device 1B. In this modified example, multiple partition walls 61, 62, and 63 are formed in the lower case 22B of the storage housing 20B. Partition walls 61 and 62 extend in the X direction, while partition wall 63 is formed in the center of the lower case 22B in the X direction, extending in the Y direction. The multiple energy storage elements 10 have the same configuration as in the first embodiment. The energy storage elements 10 are arranged along the Y direction and stacked between partition walls 61 and 62, thereby being housed in the storage housing 20B. Furthermore, the energy storage elements 10 are arranged in two rows, divided by partition wall 63.

[0049] Each power storage element 10 is bonded to the bottom surface of the lower case 22B with an adhesive. Upper case 22B has protrusions P3 and P4 extending in the Y direction (the stacking direction). Protrusions P3 and P4 protrude toward lower case 22B. Protrusions P3 and P4 abut against power storage element 10 approximately in the center of its longitudinal direction.

[0050] In this modified example, the protrusions P3 and P4 of the upper case 21B also contact the battery 10, causing the battery 10 to receive a load on the adhesive side (the lower case 22B side) and be pressed. This prevents the battery 10 from being separated from the housing 20B (lower case 22B).

[0051] Furthermore, in the above-described embodiment, a portion of the electricity storage bodies (for example, electricity storage bodies at the ends in the stacking direction) may not be in contact with the protrusions formed on the upper case.

[0052] The embodiments disclosed herein are all illustrative and not limiting. The scope of the present invention is not limited by the above description but is indicated by the technical solutions, and is intended to include all modifications within the scope of the technical solutions and equivalents.

Claims

1. A power storage device comprising: a plurality of electricity storage bodies; and The storage case includes a first case and a second case, and the plurality of electricity storage bodies are stored in a space formed by the first case and the second case. in, The plurality of electricity storage bodies are bonded to the first housing. The second housing has a protruding portion protruding toward the first housing. The protrusion is in contact with the electricity storage body.

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

3. The power storage device according to claim 1 or 2, wherein The plurality of electricity storage bodies are rectangular parallelepipeds, The electricity storage body is bonded to the first housing at the center portion in the longitudinal direction. The protrusion is in contact with the electricity storage body at a center portion in the longitudinal direction.

4. The power storage device according to claim 1 or 2, wherein The plurality of electricity storage bodies respectively include: A cell connector electrically connects a plurality of storage cells arranged along a connection direction at a connection portion; a cell housing for housing the cell connection body; and A reinforcing member is disposed at the connecting portion and is used to reinforce the battery cell housing. The protrusion abuts against the cell case at a position where the reinforcement member is arranged.

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

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