ELECTRICAL ENERGY STORAGE RESISTANCE

Abstract

An electric energy storage device includes a plurality of electric energy storage units and a housing case. The electric energy storage units are arranged in an X-direction and stacked in the X-direction. Lower surfaces of the electric energy storage units are adhered to a lower case with an adhesive member. A protruding portion extending in the X-direction is formed in an upper case. The protruding portion protrudes toward the lower case and abuts against an upper surface of the electric energy storage units. This applies stress to the electric energy storage units on the adhesive member side (lower case side) and presses them downward.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention

[0001] The invention relates to an electrical energy storage device. 2. Description of the state of the art

[0002] Japanese Unexamined Patent Application Laid-Open No. 2023-46013 (JP 2023-46013 A) discloses a battery pack in which a plurality of battery cells and the bottom of a case are bonded together with a heat transfer member having adhesive properties. SUMMARY OF THE INVENTION

[0003] There is a concern that the bond between a battery cell (electrical energy storage unit) and a casing may break if a battery pack is subjected to vibrations or similar.

[0004] An object of the present disclosure is to provide a structure in which the adhesion between the electric energy storage unit and the casing is difficult to break.

[0005] An electrical energy storage device according to the present disclosure is an electrical energy storage device comprising a plurality of electrical energy storage units and an accommodating case including a first case and a second case, and accommodating the electrical energy storage units in a space defined by the first case and the second case. The electrical energy storage units are adhered to the first case, the second case has a protruding portion protruding toward the first case, and the protruding portion abuts against the electrical energy storage units.

[0006] In this configuration, the electrical energy storage units are bonded to the first housing. The protruding portion of the second housing protrudes toward the first housing and abuts against the electrical energy storage units. The electrical energy storage units are pressed toward the first housing by the protruding portion of the second housing, thus preventing the bond between the electrical energy storage units and the housing from coming loose.

[0007] Preferably, the electric energy storage units may be arranged in the accommodation case in a stacking direction, and the protruding portion may extend in the stacking direction.

[0008] In this configuration, the electrical energy storage units can be pressed against the first housing side by the protruding portion of the second housing.

[0009] Each of the electric energy storage units may have a rectangular parallelepiped shape and may be bonded to the first case at central portions in a longitudinal direction of the electric energy storage units, and the protruding portion may abut against the electric energy storage units at the central portions in the longitudinal direction of the electric energy storage units.

[0010] According to this configuration, the central portion of the electric energy storage unit may be bonded to the housing case. Each of the electric energy storage units may include a cell assembly in which a plurality of electric energy storage cells arranged in a connection direction are electrically connected at connection portions, a cell case that houses the cell assembly, and a reinforcing member disposed at the connection portion and reinforcing the cell case. In this case, the protruding portion of the second case may abut against the cell case at a location where the reinforcing member is disposed.

[0011] According to this configuration, the protruding portion abuts against the cell case at the location where the reinforcing member is arranged, so that it is possible to appropriately press the electric energy storage units against the first case.

[0012] In addition, the cell casing may be glued to the first casing at the location where the reinforcing element is located.

[0013] According to this configuration, the cell casing is bonded to the first casing at the location where the reinforcing member is disposed, so that the force exerted by the protruding portion of the second casing on the electric energy storage unit is appropriately transmitted through the reinforcing member to the bonded location.

[0014] According to the present disclosure, it is possible to provide a structure in which the adhesion between the electric power storage unit and the casing is difficult to break. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In the following, the features, advantages and technical and industrial significance of exemplary embodiments of the invention are described with reference to the accompanying drawings, wherein like symbols designate like elements and wherein: Fig. 1 is a perspective view schematically showing an electrical energy storage device according to an embodiment; Fig. 2 is a diagram schematically showing an example of an electrical energy storage unit 10; Fig. 3A a sectional view along III-III in Fig. 1 is; Fig. 3B a sectional view along III-III in Fig. 1 is; Fig. 4 is an exploded perspective view of the electrical energy storage device according to Embodiment 2; Fig. 5 is a sectional view of an electric energy storage device according to Embodiment 2; and Fig. 6 is a perspective view schematically showing an electric power storage device 1B according to a modification. DETAILED DESCRIPTION OF EMBODIMENTS

[0016] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. The same or corresponding components are designated by the same reference numerals throughout the drawings, and their descriptions will not be repeated. In the drawings, the figures do not correspond to the actual dimensional relationships, and in order to facilitate understanding of the structure, the relationships may be changed to make the structure clearer. The embodiments and modifications described below may be selectively combined as needed. Example 1

[0017] An electric energy storage device according to the present embodiment will be described with reference to Fig. 1 to Fig. 3B described. Fig. 1 is a perspective view schematically showing the electric energy storage device according to the present embodiment.

[0018] Referring to Fig. 1, the electrical energy storage device 1 is used, for example, in a vehicle. Examples of the vehicle include a hybrid electric vehicle, a plug-in hybrid electric vehicle, a fuel cell electric vehicle, and a battery electric vehicle. The electrical energy storage device 1 includes a plurality of electrical energy storage units 10 and a housing case 20 that houses the electrical energy storage units 10.

[0019] The electrical energy storage unit 10 is a secondary battery, typically a lithium-ion battery. The lithium-ion battery is a battery that uses lithium as a charge carrier, and it can include not only a general lithium-ion secondary battery that uses a liquid electrolyte, but also a so-called all-solid-state battery that uses a solid electrolyte. Examples of lithium-ion batteries include an LFP battery that uses lithium iron phosphate as the positive electrode active material and a ternary battery that uses nickel-manganese-cobalt (NMC) as the positive electrode active material. Note that the electrical energy storage unit 10 is not limited to a lithium-ion secondary battery, but can also be a nickel-metal hydride secondary battery or other secondary batteries.

[0020] Fig. 2 is a diagram schematically showing an example of an electric energy storage unit 10. In the present embodiment, the electric energy storage unit 10 is a lamination-type lithium-ion battery in which a plurality of battery cells are laminated in a cell case, each of the battery cells being formed by laminating 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.It should be noted that the electric energy storage unit 10 may be a bipolar lithium-ion battery in which a positive electrode active material is deposited on one side of a current collector and a negative electrode active material is deposited on the other side of the current collector, and these current collectors are laminated with a separator disposed therebetween.

[0021] Referring to Fig. 2, the electrical energy storage unit 10 has a rectangular parallelepiped shape and includes 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 (longest side) extending in a Y direction. The electrical energy 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 two short side surfaces 13, 14, and the negative electrode terminal 18 is provided on the other of the two short side surfaces 13, 14. In the Fig. In the example shown in Figure 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. It should be noted that both the positive electrode terminal 17 and the negative electrode terminal 18 can be provided on either of the two short side surfaces 13, 14.

[0022] As in Fig. As can be seen in Figure 1, the accommodation case 20 includes an upper case 21 and a lower case 22. The lower case 22 has 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 portion of the bottom plate and is annular. The electrical energy storage units 10 are housed in a space formed by assembling the upper case 21 with the lower case 22. Fig. 1 shows the electrical energy storage device 1 in a state in which the upper housing 21 is removed. The upper housing 21 corresponds to an example of a "second housing" within the meaning of the present disclosure, and the lower housing 22 corresponds to an example of a "first housing" within the meaning of the present disclosure.

[0023] The electric energy storage units 10 are arranged and stacked in the X direction in a space defined by the upper case 21 and the lower case 22, and the electric energy storage units 10 are housed in the accommodation case 20. In the present embodiment, the X direction corresponds to a "stack direction" of the present disclosure.

[0024] Fig. 3A and Fig. 3B are sectional views along III-III in Fig. 1. Fig. 3A shows an example in which a central portion in the longitudinal direction of the electric energy storage unit 10 is glued, and Fig. 3B shows an example in which the entire electrical energy storage unit 10 is glued.

[0025] Referring to Fig. 3A, the lower surface 12 of the electric energy storage unit 10 and the lower case 22 are bonded to each other with an adhesive member 30 at a substantially central portion in the longitudinal direction of the electric energy storage unit 10. A protruding portion P extending in the X direction (stack direction) is formed in the upper case 21. The protruding portion P protrudes toward the lower case 22. The protruding portion P abuts against the upper surface 11 of the electric energy storage unit 10 at a substantially central portion in the longitudinal direction of the electric energy storage unit 10. The adhesive member 30 and the protruding portion P are located at locations where they overlap in a Z direction.

[0026] According to Fig. 3B, the lower surface 12 of the electric energy storage unit 10 and the lower housing 22 are bonded together with an adhesive member 30a. The adhesive member 30a bonds substantially the entire lower surface 12 of the electric energy storage unit 10 to the lower housing 22. A protruding portion P extending in the X direction (layering direction) is formed in the upper housing 21. The protruding portion P protrudes toward the lower housing 22. The protruding portion P abuts the upper surface 11 of the electric energy storage unit 10 at a substantially central portion in the longitudinal direction of the electric energy storage unit 10.

[0027] According to the embodiment of Fig. 3A, Fig. 3B, the protruding portion P of the upper housing 21 abuts against the upper surface 11 of the electric energy storage unit 10, whereby the electric energy storage unit 10 receives a load on the side of the adhesive element 30, 30a (side of the lower housing 22) and is pressed downward. This can prevent the adhesive bond between the electric energy storage unit 10 and the accommodation housing 20 (lower housing 22) from coming loose. In addition, in the configuration of Fig. 3A, the adhesive member 30 and the protruding portion P at locations where they overlap in the Z direction, so that even if the longitudinal center portion of the electric energy storage unit 10 is adhered to the lower case 22, it is possible to preferably not loosen the adhesion between the electric energy storage unit 10 and the accommodation case 20 (lower case 22).

[0028] In the configuration of Fig. 3A and Fig. 3B, a cooler for cooling the electrical energy storage unit 10 may be arranged in a space between the upper housing 21 and the upper surface 11 of the electrical energy storage unit 10. In the configuration of Fig. 3A, coolers can be arranged between the bottom surface 12 of the electrical energy storage device 10 and the lower housing 22 on both sides in the Y direction of the adhesive element 30. Example 2

[0029] Fig. 4 is an exploded perspective view of an electric energy storage unit 10A according to Embodiment 2. In Embodiment 2, the electric energy storage unit 10A includes a cell assembly 50 in which a plurality of electric energy storage cells 100 are electrically connected at connecting portions 110. The electric energy storage cell 100 is, for example, a lithium-ion battery. The electric energy storage cell 100 includes, for example, an electrode body composed of a wound body in which a positive electrode layer coated with a positive electrode active material and a negative electrode layer coated with a negative electrode active material are wound with a separator interposed therebetween, and a laminated outer body 160 that seals the electrode body.

[0030] The electric energy storage cell 100 has current collecting terminals 140 (one is a positive electrode and the other is a negative electrode) at both ends in the Y direction, and the current collecting terminals 140 of adjacent electric energy storage cells 100 are electrically connected in series at the connecting portions 110 to form the cell assembly 50. The cell assembly 50 is inserted into the cell case 300, and a cover member is connected to the cell case 300, whereby the cell assembly 50 is housed in the cell case 300 to form the electric energy storage unit 10A. Fig. 4 is a perspective view of the cell assembly 50 when the cell assembly 50 is inserted into the cell case 300. The electric energy storage unit 10A includes the cell assembly 50 in which a plurality of electric energy storage cells 100 arranged in the Y direction (connection direction) are electrically connected, and the cell case 300 in which the cell assembly 50 is housed.

[0031] A pair of reinforcement members 200 are provided at the connecting portion 110 of the cell assembly 50, sandwiching the current collection terminals 140. The reinforcement member 200 is shaped like a rectangular prism that is hollow in the Z direction. The material of the reinforcement member 200 can be synthetic resin or metal. The length of the reinforcement member 200 in the Z direction corresponds to the width of the inner surface of the cell casing 300 in the Z direction. Therefore, the reinforcement member 200 functions as a reinforcement member (so-called support rod) for the cell casing 300 at the connecting portion 110 of the cell assembly 50.

[0032] Output terminals 400 (one is a positive terminal, the other is a negative terminal) are connected to the current collection terminals 140 on both sides of the cell assembly 50. Furthermore, a pair of reinforcement members 210 similar to the reinforcement members 200 may be provided so that the current collection terminals 140 on both sides of the cell assembly 50 are interposed.

[0033] Fig. 5 is a sectional view of the electric energy storage device 1A according to Embodiment 2. This sectional view is a sectional view of a part corresponding to that of Fig. 3A, Fig. 3B. In Embodiment 2, the cell assembly 50 is formed of three electric energy storage cells 100. An accommodating case 20A includes an upper case 21A and a lower case 22A. The plurality of electric energy storage units 10A are arranged in the X direction and stacked in a space defined by the upper case 21A and the lower case 22A, thereby accommodating the electric energy storage units 10A in the accommodating case 20A.

[0034] The lower surface 12A of the electric energy storage unit 10A (the cell case 300) and the lower case 22A are bonded together with adhesive members 30A, 30A. The adhesive members 30A are provided at the locations where the reinforcement members 200 are arranged (the locations of the connecting portions 110 of the cell assembly 50), and bond the electric energy storage unit 10A and the lower case 22A together. Projecting portions P1, P2 are formed in the upper case 21 in the X direction (the stacking direction). The projecting portions P1, P2 project toward the lower case 22A. The projecting portions P1, P2 abut against the upper surface 11A of the electric energy storage unit 10A (the cell case 300). The adhesive elements 30A, 30A and the projecting portions P1, P2 are arranged at positions where they overlap in the Z direction.

[0035] According to Embodiment 2, the protruding portions P1 and P2 of the upper case 21A abut against the upper surface 11A of the electric energy storage unit 10A (the cell case 300), thereby exerting a load on the electric energy storage unit 10A and pressing it against the adhesive member 30A (the lower side of the case 22A). This can prevent the adhesive bond between the electric energy storage unit 10A and the accommodation case 20A (the lower case 22A) from coming loose. Furthermore, the protruding portions P1, P2 and the adhesive members 30A, 30A are arranged at positions where they overlap in the Z direction at the positions where the reinforcing members 200 are arranged.As a result, the force exerted by the protruding portions P1, P2 on the electric energy storage unit 10A (the cell case 300) is efficiently transmitted to the adhesive members 30A, 30A (adhesive points) through the reinforcing members 200, so that it is possible to preferably not loosen the adhesion between the electric energy storage unit 10A and the accommodating case 20A (lower case 22A).

[0036] In Embodiment 2, the cell assembly 50 is constructed from three electrical energy storage cells 100. However, the number of electrical energy storage cells 100 may also be two, four, or more. modification

[0037] Fig.6 is a perspective view schematically showing an electric power storage device 1B according to a modification. In the electric power storage device 1B of the modification, a plurality of partition walls 61, 62, 63 are formed in the lower case 22B of the storage case 20B. The partition walls 61, 62 are formed to extend in the X direction, and the partition wall 63 is formed at the central portion in the X direction of the lower case 22B to extend in the Y direction. The plurality of electric power storage units 10 have the same configuration as in Embodiment 1. The electric power storage units 10 are arranged and stacked in the Y direction between the partition wall 61 and the partition wall 62, whereby the electric power storage units 10 are accommodated in the accommodation case 20B.The electrical energy storage units 10 are also divided by the partition wall 63, whereby the electrical energy storage units 10 are arranged in two rows.

[0038] Each electric energy storage unit 10 is adhered to the bottom surface of the lower case 22B with an adhesive member. Protruding portions P3, P4 extending in the Y direction (layering direction) are formed in the upper case 22B. The protruding portions P3, P4 protrude toward the lower case 22B. The protruding portions P3, P4 abut against the electric energy storage unit 10 at a substantially central portion in the longitudinal direction of the electric energy storage unit 10.

[0039] In this modification, the protruding portions P3, P4 of the upper case 21B abut against the electric energy storage unit 10, so that the electric energy storage unit 10 experiences stress on the adhesive member side (lower case 22B side) and is pressed downward. This can prevent the adhesive bond between the electric energy storage unit 10 and the accommodation case 20B (lower case 22B) from coming off.

[0040] In the above embodiment, some of the electric energy storage units (e.g., the electric energy storage units at the end portion in stacking) may not necessarily abut against the protruding portions formed on the upper case.

[0041] The embodiments disclosed herein should be considered illustrative and not restrictive in all respects. The scope of the present disclosure is defined not by the foregoing description, but by the claims, and is intended to include meanings consistent with the claims and any modifications within the claims. QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] JP 2023-46013

[0002] JP 2023-46013 A

[0002]

Claims

[1] Electrical energy storage device comprising: a variety of electrical energy storage units; and a housing comprising a first housing and a second housing and housing the electrical energy storage units in a space defined by the first housing and the second housing, wherein: the electrical energy storage units are glued to the first housing, the second housing has a projecting portion projecting toward the first housing, and the protruding section hits the electrical energy storage units. [2] The electric energy storage device according to claim 1, wherein the electric energy storage units are arranged in the accommodating case in a stacking direction and the protruding portion extends in the stacking direction. [3] An electrical energy storage device according to claim 1 or 2, wherein: each of the electrical energy storage units has a rectangular parallelepiped shape, the electrical energy storage units are glued to the first housing at central portions in a longitudinal direction of the electrical energy storage units, and the projecting portion abuts against the electrical energy storage units at the central portions in the longitudinal direction of the electrical energy storage units. [4] An electrical energy storage device according to claim 1 or 2, wherein each of the electrical energy storage units comprises: a cell assembly in which a plurality of electric energy storage cells arranged in a connection direction are electrically connected at a connection portion; a cell housing that houses the cell assembly; and a reinforcing member disposed at the connecting portion and reinforcing the cell casing, wherein the protruding portion abuts against the cell casing at a location where the reinforcing member is disposed. [5] The electrical energy storage device according to claim 4, wherein the cell case is bonded to the first case at a location where the reinforcing member is disposed.

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