Battery stacking plate and battery stack

Abstract

A plate (50, 60, 70) for a battery stack, configured to be inserted between a plurality of energy storage modules (10), comprises: a plate-shaped housing (51, 61, 71) having a pass slot (53, 63, 73) provided in a recessed form in a first plate side face of the plate for the battery stack along a longitudinal direction thereof, the pass slot (53, 63, 73) being a groove configured to fit into a side edge section (42) of a conductive plate (40) arranged between the plurality of stacked energy storage modules (10); a plurality of first recessed holes (55, 65, 75) with bottoms, formed side by side in a direction orthogonal to a plate thickness direction of the plate for the battery stack and extending from a second plate side face opposite the first plate side face; and a plurality of second recessed holes (93) formed side by side in the direction orthogonal to the plate thickness direction and extending from a bottom section (53a, 63a, 73a) of the pass groove (53, 63, 73) to be positioned between the two adjacent first recessed holes (55, 65, 75).

Description

[0001] The present disclosure relates to a plate for a battery stack and a battery stack including the plate for the battery stack.

[0002] JP 2020 161 460 A discloses a plate for a battery stack configured to be inserted between a plurality of energy storage modules. The plate is inserted as a conductive plate between two adjacent energy storage modules in the stacking direction. The two energy storage modules are electrically connected to each other via the conductive plate. The conductive plate is provided with a plurality of flow passages and a plurality of grooves. The flow passage is a through-hole through which a coolant such as air can flow. The flow passage penetrates the conductive plate in a direction that intersects the stacking direction. The grooves are provided at both ends of the conductive plate. The number of grooves can be one, and in this case, the groove is provided only at one end. The groove penetrates the conductive plate.The conductive plate has a first wall portion and a second wall portion opposite each other in the stacking direction, and a plurality of partition walls connecting the first wall portion and the second wall portion. The partition wall is provided between the first wall portion and the second wall portion. The wall portion and the partition walls define a plurality of flow paths and a plurality of grooves.

[0003] The publication US 2017 / 0331079 A1 discloses a plate for a battery stack, which is configured to be inserted between a plurality of energy storage modules. The battery stack as a battery module comprises a base plate, end plates, battery assemblies, and the plate as partition walls. The base plate is positioned beneath the end plates, the battery assemblies, and the partition walls, so that the end plates, the battery assemblies, and the partition walls can be accommodated thereon. The partition wall is designed as a plate with parallel side walls. The side wall has a flat surface. The partition wall has a greater width at an upper side than at a lower side. The partition wall has hollow sections that extend from one end to the other between the side walls and are stacked on top of one another.The hollow sections of the partition reinforce the structural strength of the partition, thus achieving a lightweight partition by fulfilling a function similar to that of corrugated cardboard. The partition has protruding sections that define a groove on its upper surface. The protruding sections have a specific width and protrude from the upper surface of the partition.

[0004] Various energy storage devices have been proposed in the related art, and for example, an energy storage device disclosed in JP 2020-198211 A includes a plurality of stacked energy storage modules and a plurality of plate-shaped members arranged between the energy storage modules.

[0005] The majority of energy storage modules and the majority of plate-shaped members are arranged between a pair of insulating plates, and a clamping force is applied thereto by a clamping tool, thereby forming a stacked body (battery stack) having a substantially rectangular parallelepiped shape.

[0006] The energy storage module includes a resin frame, a plurality of battery cells, and a plurality of current collecting plates. The plate-shaped member includes a conductive portion (conductive plate) that electrically connects adjacent energy storage modules to each other, and an insulating portion (battery stack plate) disposed on an outer periphery of the plate-shaped member. Since the insulating portion of the plate-shaped member is disposed on an outer peripheral surface of the energy storage device, the exposure of the conductive portion from the outer peripheral surface of the energy storage device can be reduced.

[0007] The insulating portion of the plate-shaped member, which is arranged between the plurality of stacked energy storage modules as described above, is formed into a rectangular flat plate shape with a predetermined plate thickness by injection molding, for example, an insulating resin material, to maintain a predetermined spacing between the plurality of energy storage modules. However, if the thickness of the flat, plate-shaped insulating part is large, molding defects such as sink marks and warpage may occur during injection molding.

[0008] Therefore, it is conceivable to provide a plurality of recessed portions on the plate surfaces (front and back sides) of the flat, plate-shaped insulating member to reduce the thickness while ensuring compressive strength in the plate thickness direction and apparent plate thickness, thereby preventing forming defects such as sink marks and warpage. However, in a case where a plurality of recessed portions are provided on a plate surface of the insulating portion that is a stacked surface, unevenness is formed on the plate surface of the insulating portion due to the plurality of recessed portions.Therefore, when a clamping force is applied to the insulating portion of the plate-shaped member provided with the plurality of recessed portions by a clamping tool for forming a stacked body, sandwiched surfaces of the energy storage modules may be damaged or the stacked surfaces may be lifted due to inclination. Summary of the invention

[0009] The present disclosure provides a plate for a battery stack that can be advantageously inserted between a plurality of stacked energy storage modules, and a battery stack.

[0010] According to an illustrative aspect of the present disclosure, a plate for a battery stack configured to be inserted between a plurality of energy storage modules includes: a plate-shaped housing having a fitting groove provided in a depressed shape in a first plate-side surface of the plate for the battery stack along a longitudinal direction thereof, the fitting groove being a groove configured to fit into a side edge portion of a conductive plate arranged between the plurality of stacked energy storage modules; a plurality of first bottomed recessed holes formed side by side in a direction orthogonal to a plate thickness direction of the plate for the battery stack and extending from a second plate-side surface opposite to the first plate-side surface;and a plurality of second recessed holes formed side by side in the direction orthogonal to the plate thickness direction and extending from a bottom portion of the fitting groove to be positioned between the two adjacent first recessed holes;

[0011] The present disclosure has been briefly described above. Further details of the present disclosure will become clearer by reading an embodiment described below (hereinafter referred to as "Embodiment") with reference to the accompanying drawings. Brief description of the drawings Fig. 1 is an exploded perspective view of a main part of a battery stack according to an embodiment of the present disclosure. Fig. Figure 2A is an exploded perspective view of a first plate-shaped element shown in Fig. 1 is shown, and Fig. Figure 2B is an exploded perspective view of a second plate-shaped element shown in Fig. 1 is shown. Fig. 3 is an exploded perspective view of a plate for the battery stack including a battery temperature sensor mounted in Fig. 2A is shown. Fig. 4 is a perspective view from the opposite side of the housing shown in Fig. 3 is shown. Fig. 5 is a horizontal sectional view and an enlarged view of a main part of the housing shown in Fig. 3 is shown. Fig. Fig. 6 is an enlarged sectional view of a main part of a case according to a modification of the case shown in Fig. 5 is shown. Fig. Figure 7 is an exploded perspective view of a plate for the battery stack including a connection terminal shown in Fig. 2A is shown. Fig. 8 is a horizontal sectional view and an enlarged view of a main part of the housing shown in Fig. 7 is shown. Fig. 9 is a horizontal sectional view of a housing of a dummy plate for the battery stack used in Fig. 2B is shown. Fig. 10 is a perspective view of a case for a battery stack according to a reference example. Description of the embodiment

[0012] Hereinafter, an example of an embodiment according to the present disclosure will be described with reference to the drawings.

[0013] Fig. 1 is an exploded perspective view of a main part of a battery stack 1 according to the embodiment of the present disclosure. Fig. Figure 2A is an exploded perspective view of a first plate-shaped element 20 shown in Fig. 1 is shown, and Fig. Figure 2B is an exploded perspective view of a second plate-shaped element 30 shown in Fig. 1 is shown.

[0014] As in Fig. 1, the battery stack 1 according to the present embodiment includes a plurality of (four in the present embodiment) stacked energy storage modules 10 and first and second plate-shaped members (plate-shaped members) 20, 30 each positioned between the plurality of energy storage modules 10. The battery stack 1 is sandwiched between a pair of insulating plates (not shown) and formed into a substantially rectangular parallelepiped shape by a chuck (not shown).

[0015] The energy storage module 10 is formed in a rectangular, flat plate shape and includes, for example, a plurality of battery cells, a plurality of current collecting plates, and a resin frame. The battery cell includes a positive electrode mixture layer made of nickel hydroxide or the like, a negative electrode mixture layer made of a hydrogen adsorption alloy or the like, a separator formed of a porous film made of a polyolefin-based resin or the like, and an electrolytic solution.

[0016] Needless to say, the energy storage module 10 can be configured by a single battery cell, and a configuration of the battery cell is not limited to the configuration described above, and various known battery configurations can be adopted.

[0017] As in the Fig. 1, Fig. 2A and Fig. 2B, the first plate-shaped member 20 according to the present embodiment is formed in a rectangular flat plate shape including a conductive plate 40 and a plate 50 for the battery stack and a plate 60 for the battery stack, which are respectively attached to both side edge portions 42 of the conductive plate 40.

[0018] The second plate-shaped member 30 is formed in a rectangular flat plate shape including the conductive plate 40, and the plate 50 for the battery stack and a plate 70 for the battery stack are respectively attached to both side edge portions 42 of the conductive plate 40.

[0019] The conductive plate 40 is formed in an elongated rectangular plate shape from a metal such as an aluminum alloy or copper, and both side edge portions 42 in a longitudinal direction are formed in a convex piece shape having a thin plate thickness. Both side edge portions 42 of the conductive plate 40 are respectively fitted into a fitting groove 53 of the battery stack plate 50 and into each of the fitting grooves 63, 73 of the battery stack plates 60, 70.

[0020] The conductive plate 40 is a conductive portion that electrically connects the adjacent energy storage modules 10 and also serves as a heat sink that cools the adjacent energy storage modules 10.

[0021] Fig. Figure 3 is an exploded perspective view of the plate 60 for the battery stack with a battery temperature sensor 90 mounted in Fig. 2A is shown. Fig. Fig. 4 is a perspective view seen from an opposite side of a housing 61 shown in Fig. 3 is shown. Fig. Fig. 5 is a horizontal sectional view and an enlarged view of a main part of the housing 61 shown in Fig. 3 is shown.

[0022] As in Fig. 3, the plate 60 for the battery stack according to the present embodiment is configured to include the elongated rectangular plate-shaped case 61, the battery temperature sensor 90, and an electric cable 95 having one terminal connected to the battery temperature sensor 90.

[0023] The battery temperature sensor 90 is attached to the housing 61 and is arranged between the adjacent plate surfaces of the energy storage modules 10, thereby detecting the temperatures of the energy storage modules 10. The other terminal of the electric cable 95, one of which is connected to the battery temperature sensor 90, is electrically connected to a temperature detection circuit (not shown) via a connector or the like.

[0024] The housing 61 is formed by injection molding an insulating resin material into an elongated rectangular plate shape with a predetermined plate thickness t.

[0025] As in Fig. As shown in FIG. 3, a fitting groove 63 for fitting to the side edge portion 42 of the conductive plate 40 is recessed along a longitudinal direction in a plate-side surface, which is a first plate-side surface of the housing 61. A surface of a plate surface of the housing 61 in which the fitting groove 63 is fitted into the side edge portion 42 of the conductive plate 40 is configured to be flush with a surface of a plate surface of the conductive plate 40.

[0026] As in Fig. 5, on the other plate-side surface along the longitudinal direction, which is a second plate-side surface of the housing 61 opposite to the first plate-side surface, a plurality of first recessed holes 65 are formed side by side in one direction (upward direction in Fig. 5) formed orthogonally to a plate thickness direction from the second plate side surface. The plurality of first recessed holes 65 are bottomed holes, each having an opening width W1 in an arrangement direction, and are formed in a substantially rectangular parallelepiped shape so as to be arranged side by side at predetermined intervals on the second plate side surface. Therefore, ribs 64 having a predetermined pitch P1 are formed between the plurality of first recessed holes 65. The recessed holes may be referred to herein as thickness reduction holes.

[0027] Furthermore, as in Fig. 5, in a bottom portion 63a of the fitting groove 63, which is located between the two adjacent first recessed holes 65, 65, a plurality of second recessed holes 93 with bottom side by side in one direction (downward direction in Fig. 5) orthogonal to the plate thickness direction from the bottom portion 63a of the fitting groove 63.

[0028] As in Fig. 3, a sensor receiving portion 67 for receiving the battery temperature sensor 90 is formed in a third plate side surface on an end portion side (right end portion side in Fig. 5) in the longitudinal direction intersecting the first plate-side surface of the housing 61. The sensor receiving portion 67 is a recess formed by cutting out so that it penetrates from the third plate-side surface of the housing 61 in the plate thickness direction.

[0029] Guide grooves 91 formed on both side surfaces of the battery temperature sensor 90 are inserted into the sensor housing portion 67 and guided by guide ribs 67a projecting from both side walls of the sensor housing portion 67. A locking projection 92 is then locked into a locking recess 67b, so that the battery temperature sensor 90 is held in the sensor housing portion 67.

[0030] Furthermore, on the second plate side surface on one end section side (right end section side in Fig. 5) In the longitudinal direction of the housing 61, a plurality of third recessed holes 69 are formed side by side in a direction orthogonal to the plate thickness direction from the second plate-side surface to correspond to the sensor receiving portion 67. The third recessed holes 69 are bottomed holes, each having an opening width W2 in an arrangement direction and formed in a substantially rectangular parallelepiped shape so as to be arranged side by side at predetermined intervals on the second plate-side surface.

[0031] Therefore, ribs 68 having a predetermined pitch P2 are formed between the plurality of third recessed holes 69.

[0032] Additionally, in the fitting groove 63 on the one end portion side in the longitudinal direction of the housing 61, a plurality of fourth recessed holes 66 are formed side by side in a direction orthogonal to the plate thickness direction from the bottom portion 63a of the fitting groove 63 so as to correspond to the sensor receiving portion 67. The fourth recessed holes 66 are bottomed holes each having an opening width W3 in an arrangement direction and formed in a substantially rectangular parallelepiped shape so as to be arranged side by side at predetermined intervals in the bottom portion 63a of the fitting groove 63. Therefore, ribs 62 having a predetermined pitch P3 are formed between the plurality of fourth recessed holes 66.

[0033] Here, the opening width W3 in the arrangement direction and a hole depth of the fourth recessed hole 66 are each smaller than the opening width W2 in the arrangement direction and a hole depth of the third recessed hole 69. That is, the fourth recessed hole 66 is shaped to have an opening width in the arrangement direction that is narrower than that of the third recessed hole 69 and a hole depth that is shallower than that of the third recessed hole 69.

[0034] By setting the predetermined pitch P3 of the ribs 62 to the same value as the predetermined pitch P2 of the ribs 68, the rib width of the rib 62 is larger than the rib width of the rib 68. The thickness S3 between a bottom portion of the fourth recessed hole 66 and the sensor receiving portion 67 is thicker than a thickness S2 between a bottom portion of the third recessed hole 69 and the sensor receiving portion 67. Therefore, a housing portion of the sensor receiving portion 67 on the fitting groove 63 side is less likely to warp in the plate thickness direction.

[0035] As described above, according to the plate 60 for the battery stack of the present embodiment, in the plate-shaped casing 61 in which the fitting groove 63 for fitting to the side edge portion 42 of the conductive plate 40 is recessed in the first plate-side surface, it is possible to reduce the thickness of the casing 61 while ensuring compressive strength in the plate thickness direction and the apparent plate thickness t by the plurality of first recessed holes 65 with bottom formed side by side in the second plate-side surface of the casing 61 and the plurality of second recessed holes 93 formed side by side in the bottom portion 63a of the fitting groove 63 so as to correspond respectively between the two adjacent first recessed holes 65, 65, thereby preventing molding defects such as sink marks and warpage.In particular, since the second recessed hole 93 is formed at a thick portion between the bottom portions of the two adjacent first recessed holes 65, 65 and the bottom portion 63a of the fitting groove 63, it is possible to prevent sink marks at the thick portion where sink marks are likely to occur. Therefore, the plate surfaces (front and back sides) of the plate 60 for the battery stack, which are stacked surfaces, are flat surfaces without unevenness.

[0036] Therefore, in the plate 60 for the battery stack according to the present configuration, which is arranged together with the conductive plate 40 between the plurality of energy storage modules 10, when a clamping force is applied thereto by a clamping tool (not shown) to form the battery stack 1, which is a substantially rectangular parallelepiped-shaped laminated body, it is possible to prevent sandwiched surfaces of the energy storage modules 10 from being damaged or the stacked surfaces from being lifted due to inclination.

[0037] According to the plate 60 for the battery stack according to the present embodiment, the plate-shaped case 61 in which the sensor receiving portion 67 is formed by cutting so as to penetrate from the third plate side surface in the plate thickness direction includes a plurality of third bottomed recessed holes 69 formed side by side in the second plate side surface so as to correspond to the sensor receiving portion 67, and a plurality of fourth bottomed recessed holes 66 formed side by side in the bottom portion 63a of the fitting groove 63 so as to correspond to the sensor receiving portion 67. The third recessed holes 69 and the fourth recessed holes 66 can reduce the thickness while ensuring the compressive strength in the thickness direction and the apparent thickness t in housing portions on both sides of the sensor accommodating portion 67, thereby preventing sink marks.In particular, since the fourth recessed hole 66 is formed between the sensor receiving portion 67 and the bottom portion 63a of the fitting groove 63, it is possible to prevent warpage in the housing portion of the sensor receiving portion 67 on the fitting groove 63 side where warpage is likely to occur.

[0038] In the battery stack plate 60, one terminal of the electric cable 95 is connected to the battery temperature sensor 90 housed in the sensor receiving portion 67 of the case 61, and the other terminal of the electric cable 95 is electrically connected to the temperature detection circuit (not shown) so that the temperature of the energy storage module 10 can be detected.

[0039] Fig. Fig. 6 is an enlarged sectional view of a main part of a housing 61A according to a modification of the housing 61 shown in Fig. 5. In the casing 61A according to the modification, the same components as those of the above-described casing 61 are designated by the same reference numerals, and a detailed description thereof will be omitted.

[0040] As in Fig. 6, in the housing 61A according to the modification, a plurality of second recessed holes 93A are formed instead of the above-described plurality of second recessed holes 93 of the bottomed housing 61. That is, the plurality of second recessed holes 93A are arranged side by side in one direction (in Fig. 6 downwards) orthogonal to a plate thickness direction from the bottom portion 63a of the fitting groove 63 in the bottom portion 63a of the fitting groove 63 respectively formed between the two adjacent first recessed holes 65, 65 and communicate with the first recessed holes 65.

[0041] That is, the second recessed hole according to the present disclosure may take various configurations, such as the second recessed hole 93A communicating with the first recessed hole 65, the second recessed hole 93 with a bottom, and the like, according to a hole depth necessary to prevent sink marks in the thick portion.

[0042] Fig. Figure 7 is an exploded perspective view of the plate 50 for the battery stack including a connection terminal 80 shown in Fig. 2A is shown. Fig. Fig. 8 is a horizontal sectional view and an enlarged view of a main part of a housing 51 shown in Fig. 7 is shown.

[0043] As in Fig. 7, the plate 50 for the battery stack according to the present embodiment is configured to include the elongated rectangular plate-shaped case 51, the connection terminal 80, an electric cable 85 having one terminal connected to the connection terminal 80, and an insulating cover 52.

[0044] The connecting terminal 80 is made of a conductive metal material such as copper or a copper alloy and is formed in the shape of an L-shaped plate. The connecting terminal 80 has an electrical cable connecting portion 81 at one end of the L-shape and an electrical connecting portion 83 at the other end of the L-shape.

[0045] The electrical cable connecting portion 81 is electrically connected to one terminal of the electrical cable 85 by welding or the like. The other terminal of the electrical cable 85 is electrically connected to a temperature detection circuit (not shown) via a connector or the like. The electrical connecting portion 83 is electrically connected to the side edge portion 42 of the conductive plate 40 by welding or the like.

[0046] The housing 51 is formed by injection molding an insulating resin material into an elongated rectangular plate shape with the predetermined plate thickness t.

[0047] As in Fig. As shown in FIG. 8, the fitting groove 53 for fitting into the side edge portion 42 of the conductive plate 40 is recessed along a longitudinal direction in a plate-side surface, which is a first plate-side surface of the housing 51. A surface of a plate surface of the housing 51 in which the fitting groove 53 is fitted into the side edge portion 42 of the conductive plate 40 is configured to be flush with a surface of a plate surface of the conductive plate 40.

[0048] As in Fig. 7, a receiving recess 56 for receiving one terminal of the electric cable 85 and the connecting terminal 80 is formed on a plate surface (upper surface in Fig. 7) is provided on one end portion side in the longitudinal direction of the housing 51.

[0049] The receiving recess 56 includes a terminal receiving portion 56a that receives the connecting terminal 80 and an electric cable receiving portion 56b that receives one terminal of the electric cable 85.

[0050] The terminal receiving portion 56a is provided with a cutout portion 57 for bringing the electrical connection portion 83 of the connecting terminal 80 into contact with the side edge portion 42 of the conductive plate 40, which is fitted into the fitting groove 53. Therefore, when the connecting terminal 80 is housed in the terminal receiving portion 56a, the electrical connection portion 83 comes into contact with the side edge portion 42 of the conductive plate 40, and welding work is facilitated.

[0051] Since one terminal of the electric wire 85 bent in a V-shape is accommodated in the electric wire accommodation portion 56b, the tensile force can be prevented from acting on a connecting portion with the electric wire connecting portion 81 when a tensile force acts on the other terminal of the electric wire 85.

[0052] Furthermore, as in the Fig. 7 and Fig. 8 are on the other plate side surface (lower plate side surface in Fig. 8) along the longitudinal direction, which is a second plate-side surface of the housing 51 opposite to the first plate-side surface, a plurality of first recessed holes 55 side by side in one direction (upward direction in Fig. 8) formed orthogonally to a plate thickness direction from the second plate side surface. The plurality of first recessed holes 55 are bottomed holes, each having an opening width W1 in an arrangement direction and formed in a substantially rectangular parallelepiped shape so as to be arranged side by side at predetermined intervals on the second plate side surface. Therefore, ribs 54 with a predetermined pitch P1 are formed between the plurality of first recessed holes 55.

[0053] Furthermore, as in Fig. 8, in a bottom portion 53a of the fitting groove 53, which is located between the two adjacent first recessed holes 55, 55, the plurality of second recessed holes 93 are bottomed side by side in one direction (in Fig. 8 downwards) orthogonal to the plate thickness direction from the bottom portion 53a of the fitting groove 53.

[0054] As in Fig. 8, a plurality of recessed holes 59 are formed in the bottom portion 53a on one end portion side (left end side in Fig. 8) in a longitudinal direction of the fitting groove 53 so that they are side by side in one direction (downward in Fig. 5) are arranged orthogonally to the plate thickness direction. The plurality of recessed holes 59 are bottomed holes formed in a substantially rectangular parallelepiped shape so as to be arranged side by side at predetermined intervals in the bottom portion 53a of the fitting groove 53 recessed into the first plate side surface. Therefore, ribs 58 are formed between the plurality of recessed holes 59.

[0055] As in Fig. As shown in Figure 7, the insulating cover 52, formed by injection molding an insulating resin material, is attached to sandwich the housing 51 in the plate thickness direction to cover one terminal of the electric wire 85 and the connecting terminal 80 accommodated in the receiving recess 56. The insulating cover 52 covers the receiving recess 56 so that it is flush with the surface of the plate face of the housing 51.

[0056] The insulating cover 52 is attached to the housing 51 so that it is movable between a temporarily locked position and a fully locked position with respect to the housing 51. In the temporarily locked position, the insulating cover 52 exposes the electrical connection portion 83 of the connection terminal 80, which is housed in the receiving recess 56, without covering it. In the fully locked position, the insulating cover 52 completely covers the connection terminal 80, which is housed in the receiving recess 56.

[0057] As described above, according to the plate 50 for the battery stack according to the present embodiment, in the plate-shaped casing 51 in which the fitting groove 53 for fitting to the side edge portion 42 of the conductive plate 40 is recessed in the first plate side surface, it is possible to reduce a thickness of the casing 51 while ensuring compressive strength in the plate thickness direction and the apparent plate thickness t by a plurality of first recessed holes 55 formed side by side in the second plate and the plurality of second recessed holes 93 formed side by side in the bottom portion 53a of the fitting groove 53 so as to correspond respectively between the two adjacent first recessed holes 55, 55, thereby preventing molding defects such as sink marks and warpage.In particular, since the second recessed hole 93 is formed at a thick portion between the bottom portions of the two adjacent first recessed holes 55, 55 and the bottom portion 53a of the fitting groove 53, it is possible to prevent sink marks at the thick portion where sink marks are likely to occur. Therefore, the plate surfaces (front and back sides) of the plate 50 for the battery stack, which are stacked surfaces, are flat surfaces without unevenness.

[0058] The battery stack plate 50 can detect a voltage of the energy storage module 10 by electrically connecting one terminal of the electric wire 85, which is housed in the receiving recess 56 of the case 51, to the connection terminal 80, which is electrically connected to the side edge portion 42 of the conductive plate 40, and the other terminal of the electric wire 85 to a voltage detection circuit (not shown). Since the insulating cover 52 covers the receiving recess 56 so that it is flush with the surface of the plate face of the case 51, the plate faces (front and back faces) of the battery stack plate 50, which are the stacked surfaces, are flat surfaces without any unevenness.

[0059] Therefore, in the battery stack plate 50 according to the present embodiment, which is arranged together with the conductive plate 40 between the plurality of power storage modules 10, when a clamping force is applied thereto by a clamping tool (not shown) for forming the battery stack 1, which is a stacked body having a substantially rectangular parallelepiped shape, it is possible to prevent sandwiched surfaces of the power storage modules 10 from being damaged, or to prevent the plate surfaces of the battery stack plate 50 from being lifted due to inclination, and it is possible to detect the voltage of the power storage module 10.

[0060] Fig. Fig. 9 is a horizontal sectional view and an enlarged view of a main part of a case 71 of the dummy plate 70 for the battery stack shown in Fig. 2B is shown.

[0061] As in Fig. As shown in FIG. 9, the battery stack plate 70 according to the present embodiment is configured to include the elongated rectangular plate-shaped casing 71. The battery stack plate 70 is a dummy plate disposed between the plate surfaces of the adjacent energy storage modules 10 to maintain a distance between the energy storage modules 10 at a predetermined interval, and is not provided with functional components such as the connection terminal 80 and the battery temperature sensor 90.

[0062] The housing 71 is formed by injection molding an insulating resin material into an elongated rectangular plate shape with the predetermined plate thickness t.

[0063] As in the Fig. 2B and Fig. As shown in FIG. 9, the fitting groove 73 for fitting into the side edge portion 42 of the conductive plate 40 is recessed along a longitudinal direction in a plate-side surface, which is a first plate-side surface of the housing 71. A surface of a plate surface of the housing 71 in which the fitting groove 73 is fitted into the side edge portion 42 of the conductive plate 40 is configured to be flush with a surface of a plate surface of the conductive plate 40.

[0064] As in Fig. 9 are on the other plate side surface (lower plate side surface in Fig. 9) along the longitudinal direction, which is a second plate-side surface of the housing 71 opposite to the first plate-side surface, a plurality of first recessed holes 75 side by side in one direction (upward direction in Fig. 9) are formed orthogonally to a plate thickness direction from the second plate side surface. The plurality of first recessed holes 75 are bottomed holes, each having an opening width W1 and formed in a substantially rectangular parallelepiped shape, so that they are arranged side by side at predetermined intervals on the second plate side surface. Therefore, ribs 74 with a predetermined pitch P1 are formed between the plurality of first recessed holes 75.

[0065] Furthermore, as in Fig. 9, in a bottom portion 73a of the fitting groove 73, which is located between the two adjacent first recessed holes 75, 75, the plurality of second recessed holes 93 are bottomed side by side in one direction (in Fig. 9 downwards) orthogonal to the plate thickness direction from the bottom portion 73a of the fitting groove 73.

[0066] As described above, according to the plate 70 for the battery stack of the present embodiment, in the plate-shaped casing 71 in which the fitting groove 73 for fitting to the side edge portion 42 of the conductive plate 40 is recessed in the first plate side surface, it is possible to reduce a thickness of the casing 71 while ensuring compressive strength in the plate thickness direction and the apparent plate thickness t by a plurality of first recessed holes 75 formed side by side in the second plate and by the plurality of second recessed holes 93 formed side by side in the bottom portion 73a of the fitting groove 73 so as to correspond respectively between the two adjacent first recessed holes 75, 75, thereby preventing molding defects such as sink marks and warpage.In particular, since the second recessed hole 93 is formed at a thick portion between the bottom portions of the two adjacent first recessed holes 75, 75 and the bottom portion 73a of the fitting groove 73, it is possible to prevent sink marks at the thick portion where sink marks are likely to occur. Therefore, the plate surfaces (front and back sides) of the plate 70 for the battery stack, which are stacked surfaces, are flat surfaces without unevenness.

[0067] Therefore, in the plate 70 for the battery stack according to the present embodiment, which is arranged together with the conductive plate 40 between the plurality of power storage modules 10, when a clamping force is applied thereto by a clamping tool (not shown) for forming the battery stack 1, which is a stacked body having a substantially rectangular parallelepiped shape, it is possible to prevent sandwiched surfaces of the power storage modules 10 from being damaged or the plate surfaces of the plate 70 for the battery stack from being lifted due to inclination.

[0068] Then, as in Fig. 1, the two first plate-shaped members 20, each including the plate 50 for the battery stack and the plate 60 for the battery stack, which are respectively attached to both side edge portions 42 of the conductive plate 40, and the second plate-shaped member 30, which includes the plate 50 for the battery stack and the plate 70 for the battery stack, which are respectively attached to both side edge portions 42 of the conductive plate 40, are each arranged between the four energy storage modules 10 to form the battery stack 1.

[0069] Therefore, according to the battery stack 1 of the present embodiment, the first and second plate-shaped members 20, 30, each disposed between the four stacked energy storage modules 10, are composed of the conductive plate 40 that electrically connects the adjacent energy storage modules 10, and the plates 50, 60, 70 for the battery stack, each attached to the side edge portions 42 of the conductive plate 40.

[0070] Therefore, in the battery stack 1 according to the present configuration, when a clamping force is applied thereto by a clamping tool (not shown), it is possible to prevent the sandwiched surfaces of the energy storage modules 10 from being damaged or the plate surfaces of the plates 50, 60, 70 for the battery stack from being lifted due to inclination.

[0071] Fig. 10 is a perspective view of a housing 61B for a battery stack according to a reference example. Components of the housing 61B that are identical to the components of the housing 61 described above are denoted by the same reference numerals, and a detailed description is omitted.

[0072] As in Fig. As shown in Fig. 10, the housing 61B according to the reference example is formed by injection molding an insulating resin material into an elongated rectangular plate shape having the predetermined plate thickness t.

[0073] The fitting groove 63 for fitting to the side edge portion 42 of the conductive plate 40 is recessed in a plate side surface along a longitudinal direction, which is a first plate side surface of the housing 61B.

[0074] On a plate surface (upper surface in Fig. 10) of the housing 61B, a plurality of recessed portions 65B, 69B are provided at predetermined intervals along the longitudinal direction. The plurality of recessed portions 65B, 69B are bottomed holes having rectangular openings. Therefore, ribs 64B having a predetermined pitch are formed between the plurality of recessed portions 65B, and ribs 68B having a predetermined pitch are formed between the plurality of recessed portions 69B. Here, the recessed portions may be referred to as thickness reduction portions.

[0075] In this way, by providing the plurality of recessed portions 65B, 69B on the plate surface of the flat plate-shaped casing 61B, it is possible to reduce the thickness of the casing 61B while ensuring the compressive strength in the plate thickness direction and the apparent plate thickness t, and preventing forming defects such as sink marks and warpage.

[0076] However, in a case where the plurality of recessed portions 65B, 69B are provided on the plate surface of the housing 61B, which is a stacked surface, unevennesses formed by the plurality of recessed portions 65B, 69B and the ribs 64B, 68B are formed on the plate surface of the housing 61B, as shown in Fig. 10. Therefore, in the battery stack case 61B in which the plurality of recessed portions 65B, 69B are provided, when a clamping force is applied thereto by a clamping tool (not shown) to form a stacked body, sandwich surfaces of the energy storage modules 10 may be damaged or the plate surfaces of the case 61B may be lifted due to inclination.

[0077] As described above, according to the present disclosure, it is possible to provide the plates 50, 60, 70 for the battery stack, which can be advantageously inserted between the plurality of stacked energy storage modules 10 and the battery stack 1.

[0078] It should be noted that the present disclosure is not limited to the above-described embodiment, and modifications, improvements, and the like can be made as appropriate. In addition, the materials, shapes, dimensions, number, arrangement positions, and the like of components in the above-described embodiment are optional and are not limited as long as the invention can be achieved.

[0079] According to a first illustrative aspect of the present disclosure, a plate (50, 60, 70) for a battery stack configured to be inserted between a plurality of energy storage modules (10) includes: a plate-shaped housing (51, 61, 71) having a fitting groove (53, 63, 73) provided in a depressed shape in a first plate-side surface of the plate for the battery stack along a longitudinal direction thereof, the fitting groove (53, 63, 73) being a groove configured to fit in a side edge portion (42) of a conductive plate (40) arranged between the plurality of stacked energy storage modules (10); a plurality of first bottomed recessed holes (55, 65, 75) formed side by side in a direction orthogonal to a plate thickness direction of the plate for the battery stack and extending from a second plate side surface opposite to the first plate side surface;and a plurality of second recessed holes (93) formed side by side in the direction orthogonal to the plate thickness direction and extending from a bottom portion (53a, 63a, 73a) of the fitting groove (53, 63, 73) to be positioned between the two adjacent first recessed holes (55, 65, 75);

[0080] According to the plate for the battery stack of the first aspect, in the plate-shaped case in which the fitting groove for fitting to the side edge portion of the conductive plate is recessed in the first plate-side surface, it is possible to reduce a thickness while ensuring compressive strength in the plate-thickness direction and an apparent plate thickness by the plurality of bottomed first recessed holes formed side by side in the second plate-side surface of the case and the plurality of second recessed holes formed side by side in the bottom portion of the fitting groove so as to respectively correspond between the two adjacent first recessed holes, thereby preventing molding defects such as sink marks and warpage.In particular, since the second recessed hole is formed in a thick portion between the bottom portions of the two adjacent first recessed holes and the bottom portion of the fitting groove, it is possible to prevent sink marks in the thick portion where sink marks are likely to occur. Therefore, the plate surfaces (front and back sides) of the plate for the battery stack, which are stacked surfaces, are flat surfaces without unevenness.

[0081] Therefore, in the plate for the battery stack according to the present configuration, which is arranged together with the conductive plate between the plurality of energy storage modules, when a clamping force is applied thereto by a clamping tool for forming the battery stack, which is a substantially rectangular parallelepiped-shaped stacked body, it is possible to prevent the sandwiched surfaces of the energy storage modules from being damaged or the stacked surfaces from being lifted due to inclination.

[0082] According to a second illustrative aspect of the present disclosure, the plate (60) for the battery stack may further include: a recess (67) formed to penetrate in the plate thickness direction and extend from a third plate side surface that intersects with the first plate side surface; a plurality of third bottomed recessed holes (69) formed side by side in the direction orthogonal to the plate thickness direction and extending from the second plate side surface at a position corresponding to the recess (67); and a plurality of fourth bottomed recessed holes (66) formed side by side in the direction orthogonal to the plate thickness direction and extending from the bottom portion (63a) of the fitting groove (63) at the position corresponding to the recess (67).An opening width (W3) in a direction in which the fourth recessed holes (66) are arranged may be narrower than an opening width (W2) in a direction in which the third recessed holes (69) are arranged, and a hole depth of the fourth recessed holes (66) may be shallower than a hole depth of the third recessed holes (69).

[0083] According to the plate for the battery stack of the second aspect, the plate-shaped case in which the recess is formed by cutting to penetrate from the third plate side surface in the plate thickness direction includes the plurality of third bottomed recessed holes formed side by side in the second plate side surface to correspond to the recess, and the plurality of fourth bottomed recessed holes formed side by side in the lower portion of the fitting groove to correspond to the recess. The third recessed holes and the fourth recessed holes can reduce the thickness while ensuring the compressive strength in the plate thickness direction and the apparent plate thickness in the case portions on both sides of the recess, thereby preventing sink marks.In particular, since the fourth recessed hole is formed between the recess and the bottom portion of the fitting groove, it is possible to prevent warpage in the housing portion on the fitting groove side of the recessed portion where warpage is likely to occur.

[0084] According to a third illustrative aspect of the present disclosure, the plate (60) for the battery stack may further include: a battery temperature sensor (90) housed in the recess (67); and an electric cable (95) having one terminal connected to the battery temperature sensor (90).

[0085] According to the battery stack plate of the third aspect, one terminal of the electric wire is connected to the battery temperature sensor housed in the recess of the case, and the other terminal of the electric wire is electrically connected to a temperature detection circuit so that a temperature of the energy storage module can be detected. Since the battery temperature sensor housed in the recess of the case is flush with a surface of a plate surface of the case, the plate surfaces (front and back sides) of the battery stack plate, which are stacked surfaces, are flat surfaces without unevenness.

[0086] Therefore, in the plate for the battery stack according to the present configuration, which is arranged together with the conductive plate between the plurality of energy storage modules, when a clamping force is applied thereto by a clamping tool for forming the battery stack, which is a substantially rectangular parallelepiped stacked body, sandwiched surfaces of the energy storage modules can be prevented from being damaged or the stacked surfaces from being lifted due to inclination, and it is possible to detect the temperature of the energy storage module.

[0087] According to a fourth illustrative aspect of the present disclosure, a battery stack (1) may include the plate (50, 60, 70) for the battery stack according to any one of the first to third aspects.

[0088] According to the battery stack of the fourth aspect, each of the plate-shaped members arranged between the plurality of stacked energy storage modules includes the conductive plate electrically connecting the adjacent energy storage modules, and the plate for the battery stack suitably attached to each side edge portion of the conductive plate.

[0089] Therefore, in the battery stack according to the present configuration, which is arranged together with the conductive plate between the plurality of energy storage modules, the sandwiched surfaces of the energy storage modules can be prevented from being damaged or the plate surfaces of the plate for the battery stack from being lifted due to inclination when a clamping force is applied thereto by a clamping tool.

[0090] According to the present disclosure, it is possible to provide a plate for a battery stack that can be advantageously inserted between a plurality of stacked energy storage modules and a battery stack.

Claims

[1] A plate (50, 60, 70) for a battery stack configured to be inserted between a plurality of energy storage modules (10), comprising: a plate-shaped housing (51, 61, 71) having a fitting groove (53, 63, 73) provided in a recessed shape in a first plate side surface of the plate for the battery stack along a longitudinal direction thereof, the fitting groove (53, 63, 73) being a groove configured to fit in a side edge portion (42) of a conductive plate (40) arranged between the plurality of stacked energy storage modules (10); a plurality of first bottomed recessed holes (55, 65, 75) formed side by side in a direction orthogonal to a plate thickness direction of the plate for the battery stack and extending from a second plate side surface opposite to the first plate side surface; and a plurality of second recessed holes (93) formed side by side in the direction orthogonal to the plate thickness direction and extending from a bottom portion (53a, 63a, 73a) of the fitting groove (53, 63, 73) to be positioned between the two adjacent first recessed holes (55, 65, 75). [2] The plate (60) for the battery stack according to claim 1, further comprising: a recess (67) formed to penetrate in the plate thickness direction and extend from a third plate side surface intersecting with the first plate side surface; a plurality of third bottomed recessed holes (69) formed side by side in the direction orthogonal to the plate thickness direction and extending from the second plate side surface at a position corresponding to the recess (67); and a plurality of fourth recessed holes (66) with bottom formed side by side in the direction orthogonal to the plate thickness direction and extending from the bottom portion (63a) of the fitting groove (63) in the corresponding position to the recess (67), wherein an opening width (W3) in a direction in which the fourth recessed holes (66) are arranged is narrower than an opening width (W2) in a direction in which the third recessed holes (69) are arranged, and a hole depth of the fourth recessed holes (66) is shallower than a hole depth of the third recessed holes (69). [3] The plate (60) for the battery stack according to claim 2, further comprising: a battery temperature sensor (90) housed in the recess (67); and an electrical cable (95), one terminal of which is connected to the battery temperature sensor (90). [4] A battery stack (1) comprising: the plate (50, 60, 70) for the battery stack according to any one of claims 1 to 3.

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