Power storage device

Abstract

To provide a power storage device capable of suppressing deterioration of periphery parts of a plurality of battery cells due to load while suppressing deterioration of the plurality of battery cells due to heat.SOLUTION: The power storage device according to the present disclosure includes: a plurality of battery cells stacked; a plurality of heat-insulating plates between the plurality of battery cells; and a case accommodating a cell stack having the battery cells and the heat-insulating plates. Each of the heat-insulating plates is formed so as to cover the entire stacking surface of the battery cell adjacent to the heat-insulating plate and has a tapered edge not contacting the edge of the battery cell adjacent to the heat-insulating plate.SELECTED DRAWING: Figure 7

Description

[Technical Field]

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

[0002] Patent Document 1 discloses a battery module including a plurality of stacked battery cells and a plurality of buffer sheets arranged alternately with the plurality of battery cells. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2023-46073 Summary of the Invention [Problem to be solved by the invention]

[0004] In the battery module disclosed in Patent Document 1, if each buffer sheet is arranged to cover the entire stacking surface of the battery cell adjacent to it in order to prevent heat transfer between the multiple battery cells, the buffer sheet may apply a load to the peripheral edges of the adjacent battery cells, which may result in deterioration of the peripheral edges of the battery cells. On the other hand, if each buffer sheet is arranged to cover the stacking surface of the battery cell adjacent to it except for the peripheral edges in order to prevent deterioration of the peripheral edges of the multiple battery cells, heat may be more easily transferred between the multiple battery cells via the peripheral edges, which may result in deterioration of each battery cell due to heat. In other words, the battery module disclosed in Patent Document 1 has the problem of being unable to prevent deterioration of the peripheral edges of the multiple battery cells due to load while preventing deterioration of the multiple battery cells due to heat.

[0005] The present disclosure has been made in consideration of the above background, and aims to provide an energy storage device that can suppress deterioration of the peripheral portions of multiple battery cells due to load while suppressing deterioration of multiple battery cells due to heat. [Means for solving the problem]

[0006] The energy storage device according to the present disclosure includes a plurality of stacked battery cells, a plurality of insulating plates disposed between the plurality of battery cells, and a case housing a cell stack including the plurality of battery cells and the plurality of insulating plates. Each insulating plate is formed to cover the entire stacking surface of the battery cell adjacent to the insulating plate and has a tapered edge so as not to contact the edge of the battery cell adjacent to the insulating plate. In this energy storage device, each insulating plate is formed to cover the entire stacking surface of the battery cell adjacent to the insulating plate. This reduces heat transfer between the plurality of battery cells, thereby suppressing heat-induced deterioration of each battery cell. Furthermore, in this energy storage device, each insulating plate has a tapered edge so as not to contact the peripheral edge of the battery cell adjacent to the insulating plate. This reduces the load applied from each insulating plate to the peripheral edge of the adjacent battery cell, thereby suppressing load-induced deterioration of the peripheral edge of each battery cell. That is, this power storage device can suppress deterioration of the peripheral portions of the plurality of battery cells due to load, while suppressing deterioration of the plurality of battery cells due to heat. [Effects of the Invention]

[0007] The present disclosure makes it possible to provide an electricity storage device that can suppress deterioration of the peripheral portions of the plurality of battery cells due to load, while suppressing deterioration of the plurality of battery cells due to heat. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a schematic perspective view showing the appearance of a replaceable battery according to a first embodiment. [Figure 2] 3 is a schematic perspective view showing an enlarged view of the periphery of a front case provided at the front end of the replaceable battery according to the first embodiment. FIG. [Figure 3] 3 is a schematic perspective view showing an enlarged view of the periphery of a rear case provided at the rear end of the replaceable battery according to the first embodiment. FIG. [Figure 4]4 is a flowchart showing the flow of assembling the replaceable battery according to the first embodiment. [Figure 5] 1 is a schematic perspective view for explaining the assembly flow of the replaceable battery according to the first embodiment. FIG. [Figure 6] 1 is a schematic perspective view for explaining the assembly flow of the replaceable battery according to the first embodiment. FIG. [Figure 7] 2 is a schematic cross-sectional view of the ZX plane of the replaceable battery according to the first embodiment. FIG. [Figure 8] 1 is a schematic exploded view of a cell stack provided in a replaceable battery according to a first embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0009] The present invention will be described below through embodiments of the invention, but the invention according to the claims is not limited to the following embodiments. Furthermore, not all of the configurations described in the embodiments are necessarily essential means for solving the problems. For clarity of explanation, the following description and drawings have been omitted and simplified as appropriate. In each drawing, the same elements are given the same reference numerals, and repeated explanations are omitted as necessary.

[0010] <First Embodiment> FIG. 1 is a schematic perspective view showing the appearance of a replaceable battery 1 according to a first embodiment. The replaceable battery 1 is also called a battery pack, a battery module, or the like, and is detachably mounted on a vehicle such as an electric vehicle that runs on a motor powered by electricity. The replaceable battery 1 is made small and lightweight so that, for example, an operator can easily insert or remove it from the electric vehicle. The operator also includes a work robot, etc.

[0011] As shown in Fig. 1, the replaceable battery 1 has a rectangular parallelepiped outer shape defined by a case 100 that houses a cell stack and other components. The case 100 includes a rectangular cylindrical case body 101, a front case 102 that is a lid that closes the opening at the front end of the case body 101 (i.e., one open end), and a rear case 103 that is a lid that closes the opening at the rear end of the case body 101 (i.e., the other open end). The rear case 103, located at the rear end of the replaceable battery 1, is provided with a connector 104 that protrudes outward and is connectable to a connector on the vehicle. For example, an operator places the replaceable battery 1 in a vehicle storage space by sliding it in the longitudinal direction (X-axis direction), thereby connecting the connector 104 of the replaceable battery 1 to the connector on the vehicle.

[0012] 2 is a schematic perspective view showing an enlarged view of the periphery of the front case 102 provided at the front end of the replaceable battery 1. As shown in FIG. 2, the front case 102 is provided with a pull tab 141 for sliding the replaceable battery 1. An operator can slide the replaceable battery 1 by grasping the pull tab 141 and pushing or pulling the replaceable battery 1.

[0013] The replaceable battery 1 can also be transported by placing it on a cart, for example. When storing the replaceable battery 1 from the cart into a storage space, the height of the cart is adjusted to match the storage space, and the handle 141 is pressed to store the replaceable battery 1 in the storage space. On the other hand, when removing the replaceable battery 1 from the storage space and placing it on the cart, the height of the cart is adjusted to match the storage space, and the handle 141 is pulled to remove the replaceable battery 1 from the storage space.

[0014] 3 is a schematic perspective view showing an enlarged view of the periphery of the rear case 103 provided at the rear end of the replaceable battery 1. As shown in FIG. 3, the rear case 103 is provided with a handle 131 and a relief valve 132 in addition to the connector 104.

[0015] The connector 104 includes a base 1041, a high-voltage terminal 1042, a low-voltage terminal 1043, an alignment pin 1044, and a metal cover 1045. The base 1041 is disposed on the main surface of the rear case 103. The high-voltage terminal 1042, the low-voltage terminal 1043, and the alignment pin 1044 are all formed to protrude outward from the main surface of the base 1041. The cover 1045 is formed to surround the side surfaces of the high-voltage terminal 1042 and the low-voltage terminal 1043. The high-voltage terminal 1042 is a terminal for transmitting electricity output from the cell stack housed in the case 100 of the replaceable battery 1 to a vehicle in which the replaceable battery 1 is mounted. The low-voltage terminal 1043 is a terminal for transmitting a control signal from the vehicle to the replaceable battery 1 and a signal indicating the cell stack monitoring results (such as voltage measurement results) from the replaceable battery 1 to the vehicle.

[0016] The relief valve 132 discharges gas generated in the cell stack housed in the case 100 of the replaceable battery 1. Even if gas is discharged from the relief valve 132, the high-voltage terminal 1042 and the low-voltage terminal 1043 are protected by the metal cover 1045.

[0017] The handle 131 is rotatable around an axis extending along the upper edge of the rear case 103, and is placed on the top surface of the case body 101 when not in use. Therefore, the rear end of the replaceable battery 1 can be hung by the handle 131 and carried without interfering with the connection of the connector 104.

[0018] More specifically, when carrying the replacement battery 1, the worker holds the rotatable handle 131 with one hand to lift the replacement battery 1, while holding the pull tab 141 with the other hand to support the replacement battery 1. This allows the worker to carry the replacement battery 1 while stabilizing its center of gravity (maintaining balance).

[0019] Here, a rib groove 101c is formed on the top surface of the case body 101 along the longitudinal direction (X-axis direction) of the case body 101. Therefore, the handle 131 is stored in the rib groove 101c when not in use. This makes it easier for an operator to store the replaceable battery 1 in the storage space of the vehicle. Furthermore, by forming the rib groove 101c, the strength of the top surface of the case body 101 is also improved.

[0020] It is preferable that the thickness of case body 101 is small and that the thickness of rear case 103 is larger than that of case body 101. Reducing the thickness of case body 101 reduces the weight of case 100, and providing handle 131 on thick rear case 103 suppresses deformation of case 100. For example, a die-cast member is used for rear case 103. This configuration improves the rigidity of rear case 103 on which handle 131 is provided, and also improves the ease of use of handle 131 when in use. Furthermore, by reducing the thickness of case body 101, even if gas is generated in cell stack 110, case body 101 elastically deforms and expands outward, suppressing a sudden increase in internal case pressure.

[0021] Next, the assembly flow of the replaceable battery 1 will be described while explaining the contents contained in the case 100 of the replaceable battery 1 using Figures 4 to 6. Figure 4 is a flowchart showing the assembly flow of the replaceable battery 1. Figures 5 and 6 are schematic perspective views for explaining the assembly flow of the replaceable battery 1. The display contents of steps S101 to S105 in Figures 5 and 6 correspond to the processing results of steps S101 to S105 in Figure 4.

[0022] First, the lower case 101b, which forms the bottom plate and one side plate of the case body 101, is arranged (step S101). The lower case 101b is formed so that its YZ cross section is L-shaped and extends along the X-axis direction. A pair of rails 106 is provided below the bottom plate formed by the lower case 101b, along the longitudinal direction (X-axis direction) of the lower case 101b. This makes it easier for the replaceable battery 1 to slide along the guide. In addition, a metal member 105 is provided above the bottom plate, along the longitudinal direction of the lower case 101b. The metal member 105 is formed of, for example, aluminum or an alloy containing aluminum (i.e., a metal mainly composed of aluminum).

[0023] Thereafter, a rectangular parallelepiped cell stack 110 is placed on the top side of the bottom plate formed by the lower case 101b, close to one of the side plates formed by the lower case 101b (step S102). The cell stack 110 includes a plurality of stacked battery cells and heat insulating plates provided between the plurality of battery cells. The cell stack 110 is bound into a rectangular parallelepiped shape by binding members 111 such as cable ties. Here, metal members 105 provided on the top side of the bottom plate formed by the lower case 101b and below the cell stack 110 serve to release heat from the cell stack 110 to the outside of the case 100.

[0024] Thereafter, electronic devices such as a junction box 108 including relays and the like and a battery monitoring device 107 are further arranged above the bottom plate formed by the lower case 101b (step S103). The battery monitoring device 107 includes a voltage measuring device that measures the voltage of the cell stack 110 and the voltage of each battery cell that constitutes the cell stack. The battery monitoring device 107 is arranged in a spatial region between the cell stack 110 and the other side plate of the case body 101, which will be described later, within the region above the bottom plate formed by the lower case 101b. This spatial region is formed by arranging the cell stack 110 close to one side plate of the case body 101. The junction box 108 is arranged in a spatial region between the rear end of the cell stack 110 and a rear case 103, which will be described later.

[0025] Furthermore, the inner case 102a of the front case 102 is disposed at the front end of the lower case 101b (case body 101) (step S103). The rear case 103 having the connector 104 is disposed at the rear end of the lower case 101b (case body 101) (step S103). The rear end of the cell stack 110 and the rear case 103 are connected via support rods 114. This ensures a sufficient space between the rear end of the cell stack 110 and the rear case 103 for disposing the junction box 108. Furthermore, by connecting the front end of the cell stack 110 to the front case 102 having the pull tab 141 and by connecting the rear end of the cell stack 110 to the rear case 103 having the handle 131 via the support rods 114, the load on the case body 101 is reduced when an operator lifts the replaceable battery 1 by grasping the pull tab 141 and the handle 131.

[0026] Thereafter, the upper case 101a, which forms the top plate and the other side plate of the case body 101, is arranged to face the lower case 101b (step S104). The upper case 101a is formed so that its YZ cross section is L-shaped and extends along the X-axis direction. The upper case 101a and the lower case 101b form the rectangular cylindrical case body 101. Within the interior area of ​​this case body 101, a spatial region 160 is provided above the cell stack 110. This spatial region 160 is also used as a smoke exhaust region for releasing gas generated in the cell stack 110. For example, gas generated in the cell stack 110 is discharged from the spatial region 160 to the outside of the case 100 via the relief valve 132.

[0027] Furthermore, the upper case 101a and the lower case 101b are fastened together by fastening members 151 and 152 (step S104).

[0028] Thereafter, the outer case 102b of the front case 102 is placed on the front end of the case body 101. This completes the replacement battery 1 (step S105). The case 102b has a cap shape and is attached so as to enclose the opening (open end) at the front end of the case body 101 from the side as well. This makes it possible to prevent gas from leaking from the front case 102 side where the worker is working, before the gas is discharged from the relief valve 132.

[0029] Fig. 7 is a schematic cross-sectional view of the ZX plane of the replaceable battery 1. As shown in Fig. 7, in the replaceable battery 1, the front end of the cell stack 110 is connected to a front case 102 having a pull tab 141, and the rear end of the cell stack 110 is connected to a rear case 103 having a handle 131 via a support rod 114. This reduces the load on the case body 101 when an operator lifts the replaceable battery 1 by grasping the pull tab 141 and the handle 131. This allows the thickness of the case body 101 of the replaceable battery 1 to be reduced, thereby achieving a lighter weight.

[0030] As shown in FIG. 7, the cell stack 110 includes multiple heat insulating plates 110b between the stacked battery cells 110a. FIG. 8 is a schematic exploded view of the cell stack 110. Each battery cell 110a has a rectangular stacking surface, and each heat insulating plate 110b also has a rectangular stacking surface. Each heat insulating plate 110b is composed of an insulating material, for example, solidified insulating powder such as silica, and a film that encases the insulating material. Each heat insulating plate 110b is formed to cover the entire stacking surface of the battery cell 110a adjacent to it. This reduces heat transfer between the multiple battery cells 110a, thereby suppressing thermal deterioration of each battery cell 110a. Each heat insulating plate 110b also has a tapered edge 110c so as not to come into contact with the peripheral edge (edge) of the battery cell 110a adjacent to it. This reduces the load applied from each heat insulating plate 110b to the periphery of the adjacent battery cell 110a, thereby suppressing deterioration of the periphery of each battery cell 110a due to the load.

[0031] As described above, in the replaceable battery 1 according to the present disclosure, each heat insulating plate 110b is formed to cover the entire stacking surface of the battery cells 110a adjacent to the heat insulating plate. This reduces heat transfer between the multiple battery cells 110a, thereby suppressing thermal degradation of each battery cell 110a. Furthermore, each heat insulating plate 110b has a tapered edge 110c so as not to contact the peripheral edge (edge) of the battery cell 110a adjacent to the heat insulating plate. This reduces the load applied from each heat insulating plate 110b to the peripheral edge of the adjacent battery cell 110a, thereby suppressing load-induced degradation of the peripheral edge of each battery cell 110a. In other words, the replaceable battery 1 according to the present disclosure can suppress load-induced degradation of the peripheral edge of the multiple battery cells 110a while suppressing heat-induced degradation of the multiple battery cells 110a.

[0032] The present invention is not limited to the above-described embodiment, and can be modified as appropriate within the scope of the invention.

[0033] In this disclosure, a case has been described in which, in a cell stack mounted on a replaceable battery 1, each heat insulating plate is formed to cover the entire stacking surface of the battery cell adjacent to the heat insulating plate and has a tapered edge so as not to contact the edge of the battery cell adjacent to the heat insulating plate, but this is not limited thereto. The cell stack according to this disclosure may be applied to various power storage devices other than replaceable batteries. [Explanation of symbols]

[0034] 1 replaceable battery 100 cases 101 Case body (main body) 101a Upper case (second case member) 101b Lower case (first case member) 102 Front case (first lid) 102a Inner case 102b Outer case 103 Rear case (second lid) 104 Connector 105 Metallic parts 106 Rail 107 Battery monitoring device 108 Junction Box 110 Cell Stack 110a battery cell 110b Heat insulating board 110c edge 111 Binding member 114 Support rod 131 Toride 132 Relief valve 141 Pull handle 151 Fastening members 152 Fastening members 160 Spatial domain 1041 Pedestal 1042 High voltage terminal 1043 Low voltage terminal 1044 pins 1045 Cover

Claims

1. A plurality of stacked battery cells; a plurality of heat insulating plates provided between the plurality of battery cells; a case that houses a cell stack including the plurality of battery cells and the plurality of heat insulating plates; A power storage device comprising: Each heat insulating plate is formed to cover the entire stacking surface of the battery cell adjacent to that heat insulating plate, and has a tapered edge so as not to come into contact with the edge of the battery cell adjacent to that heat insulating plate. Energy storage device.

2. Each of the heat insulating plates is an insulating material in which insulating powder is solidified; a film that wraps the thermal insulation material; The power storage device according to claim 1 .

3. The heat insulating board comprises silica. The power storage device according to claim 1 .

4. the plurality of battery cells have rectangular stacking surfaces; The plurality of heat insulating plates have rectangular stacking surfaces. The power storage device according to claim 1 .

Images