Electricity storage device

Abstract

A power storage device according to the present disclosure is provided with: a plurality of stacked battery cells; the plurality of heat insulation plates are arranged among the plurality of battery cells; and a case that accommodates a cell stack having a plurality of battery cells and a plurality of heat-insulating plates, each heat-insulating plate being formed so as to cover the entire surface of the laminated surface of the battery cells adjacent to the heat-insulating plate, and having a tapered edge portion so as not to come into contact with the edges of the battery cells adjacent to the heat-insulating plates.

Description

Technical Field

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

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

[0003] Patent Document 1: Japanese Patent Application Laid-Open No. 2023-46073

[0004] In the battery module disclosed in Patent Document 1, if each buffer sheet is arranged to cover the entire surface of the stacked battery cells adjacent to the sheet in order to prevent heat transfer between the multiple battery cells, a load is applied from the buffer sheet to the peripheral edge of the adjacent battery cells, potentially causing degradation of the peripheral edge of the battery cells. On the other hand, if each buffer sheet is arranged to cover the surface of the stacked battery cells adjacent to the sheet other than the peripheral edge in order to prevent degradation of the peripheral edge of the multiple battery cells, heat transfer between the multiple battery cells is facilitated through the peripheral edge, potentially causing degradation of the battery cells due to heat. In other words, the battery module disclosed in Patent Document 1 suffers from the problem of being unable to prevent degradation of the peripheral edge of the multiple battery cells caused by load, and unable to prevent degradation of the multiple battery cells due to heat. Summary of the Invention

[0005] The present disclosure has been made in view of the above background, and an object of the present disclosure is to provide a power storage device capable of suppressing degradation of the peripheral portions of a plurality of battery cells due to load and suppressing degradation of the plurality of battery cells due to heat.

[0006] The power storage device disclosed herein comprises: a plurality of stacked battery cells; a plurality of heat shields disposed between the battery cells; and a housing that houses the cell stack comprising the plurality of battery cells and the heat shields. Each heat shield is formed to cover the entire surface of the stacked battery cells adjacent to the heat shield and has a tapered edge portion that prevents contact with the edge of the battery cells adjacent to the heat shield. In this power storage device, each heat shield is formed to cover the entire surface of the stacked battery cells adjacent to the heat shield. This reduces heat transfer between the battery cells, thereby suppressing thermal degradation of the battery cells. Furthermore, in this power storage device, each heat shield has a tapered edge portion that prevents contact with the peripheral edge of the battery cells adjacent to the heat shield. This reduces the load applied by each heat shield to the peripheral edge of the adjacent battery cells, thereby suppressing load-induced degradation of the peripheral edge of the battery cells. That is, this power storage device can suppress degradation of the peripheral portions of the plurality of battery cells due to load, and can also suppress degradation of the plurality of battery cells due to heat.

[0007] According to the present disclosure, it is possible to provide a power storage device that can suppress degradation of the peripheral portions of a plurality of battery cells due to load and suppress degradation of the plurality of battery cells due to heat. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] The above objects and other objects, features and advantages of the present disclosure will be more fully understood from the following detailed description and accompanying drawings.

[0009] Figure 1 This is a schematic perspective view showing the appearance of the replaceable battery according to the first embodiment.

[0010] Figure 2 This is a schematic enlarged perspective view of the periphery of a front case provided at the front end of the replaceable battery according to the first embodiment.

[0011] Figure 3 This is a schematic enlarged perspective view of the periphery of a rear case provided at the rear end of the replaceable battery according to the first embodiment.

[0012] Figure 4 This is a flowchart showing the flow of assembling the replaceable battery according to the first embodiment.

[0013] Figure 5 This is a schematic perspective view for explaining the assembly process of the replaceable battery according to the first embodiment.

[0014] Figure 6 This is a schematic perspective view for explaining the assembly process of the replaceable battery according to the first embodiment.

[0015] Figure 7 This is a schematic cross-sectional view of the replaceable battery according to the first embodiment, taken along the ZX plane.

[0016] Figure 8 This is a schematic exploded view of a cell stack provided in the replaceable battery according to the first embodiment. DETAILED DESCRIPTION

[0017] The present invention will be described below using embodiments of the invention. However, the inventions described in the claims are not limited to the following embodiments. In addition, not all of the structures described in the embodiments are necessary as means for solving the problems. For the sake of clarity, the following description and drawings have been appropriately omitted and simplified. In each drawing, the same elements are marked with the same reference numerals, and repeated descriptions are omitted as needed.

[0018] <Implementation Method 1>

[0019] Figure 1 This is a simplified perspective view showing the appearance of a replaceable battery 1 according to Embodiment 1. The replaceable battery 1, also known as a battery pack or battery module, is removably mounted on, for example, an electric vehicle powered by a motor. For example, the replaceable battery 1 is miniaturized and lightweight to facilitate insertion and removal from the electric vehicle by an operator. Furthermore, operators also include operating robots and the like.

[0020] like Figure 1 As shown, in the replaceable battery 1, the outer shape of the rectangular parallelepiped is defined by the housing 100 that accommodates the battery cell stack and the like. The housing 100 includes a housing body 101 in the shape of a square cylinder, a front housing 102 that is a cover that closes the opening at the front end of the housing body 101 (i.e., one open end), and a rear housing 103 that is a cover that closes the opening at the rear end of the housing body 101 (i.e., the other open end). In addition, the rear housing 103, which is provided at the rear end of the replaceable battery 1, is provided with a connector 104 that protrudes outward and is formed to be connectable to a connector on the vehicle side. For example, the operator slides the replaceable battery 1 in the longitudinal direction (X-axis direction) and accommodates it in the vehicle's storage space, thereby connecting the connector 104 of the replaceable battery 1 to the connector on the vehicle side.

[0021] Figure 2 This is a simplified perspective view of the periphery of the front housing 102 provided at the front end of the replaceable battery 1 after enlargement. Figure 2 As shown, a handle 141 for sliding the replaceable battery 1 is provided on the front case 102. The operator can slide the replaceable battery 1 by gripping the handle 141 and pressing and pulling the replaceable battery 1.

[0022] Alternatively, the replaceable battery 1 can be transported by being placed on a cart, for example. When placing the replaceable battery 1 from the cart into the storage space, the height of the cart is aligned with the storage space, and the handle 141 is pressed to place the replaceable battery 1 into 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 aligned with the storage space, and the handle 141 is pulled to remove the replaceable battery 1 from the storage space.

[0023] Figure 3 This is a simplified perspective view of the periphery of the rear housing 103 provided at the rear end of the replaceable battery 1 after enlargement. Figure 3 As shown, in addition to the connector 104 , the rear housing 103 is also provided with a handle 131 and a safety valve 132 .

[0024] 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 arranged on the main surface of the rear housing 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 battery cell stack housed in the housing 100 of the replaceable battery 1 to the vehicle on which the replaceable battery 1 is installed. The low-voltage terminal 1043 is a terminal for transmitting control signals from the vehicle to the replaceable battery 1 and transmitting signals indicating monitoring results (voltage measurement results, etc.) of the battery cell stack from the replaceable battery 1 to the vehicle.

[0025] Safety valve 132 discharges gas generated in the cell stack housed in housing 100 of replaceable battery 1. Even when gas is discharged from safety valve 132, high-voltage terminal 1042 and low-voltage terminal 1043 are protected by metal cover 1045.

[0026] The handle 131 is rotatable about an axis extending along the upper edge of the rear housing 103 and is placed on the upper surface of the housing body 101 when not in use. Therefore, the rear end of the replaceable battery 1 can be lifted by the handle 131 for transportation without interfering with the connection of the connector 104.

[0027] More specifically, when carrying the replaceable battery 1, the operator holds the rotatable handle 131 with one hand to lift the replaceable battery 1, and holds the handle 141 with the other hand to support the replaceable battery 1. This allows the operator to carry the replaceable battery 1 while stabilizing the center of gravity (maintaining balance).

[0028] Here, a rib groove 101c is formed on the upper surface of the housing body 101 along the longitudinal direction (X-axis direction) of the housing body 101. Therefore, when not in use, the handle 131 is accommodated in the rib groove 101c. This makes it easier for the operator to place the replaceable battery 1 in the vehicle's storage space. Furthermore, the formation of the rib groove 101c improves the strength of the upper surface of the housing body 101.

[0029] In addition, it is preferred that the thickness of the shell body 101 is small, and the thickness of the rear shell 103 is greater than the thickness of the shell body 101. By reducing the thickness of the shell body 101, the shell 100 is lightweight, and by providing the handle 131 on the thick rear shell 103, the deformation of the shell 100 is suppressed. For example, a die-cast component is used as the rear shell 103. With such a structure, the rigidity of the rear shell 103 provided with the handle 131 is improved, and the operability of the handle 131 when used is also improved. In addition, by reducing the thickness of the shell body 101, even when gas is generated in the battery stack 110, the shell body 101 is elastically deformed and expands outward, thereby suppressing a sharp increase in the pressure inside the shell.

[0030] Next, use Figures 4 to 6 , the contents of the housing 100 of the replaceable battery 1 are described, and the assembly process of the replaceable battery 1 is described. Figure 4 This is a flowchart showing the flow of assembling the replaceable battery 1 . Figure 5 and Figure 6 This is a schematic perspective view for explaining the assembly process of the replaceable battery 1 . Figure 5 and Figure 6 The display contents of steps S101 to S105 in Figure 4 The processing results of steps S101 to S105 correspond to each other.

[0031] First, a lower shell 101b is configured to form a bottom plate and a side plate of the shell body 101 (step S101). The lower shell 101b is formed into an L-shape in the YZ cross-section and extends along the X-axis direction. On the lower side of the bottom plate formed by the lower shell 101b, a pair of guide rails 106 are provided along the long side direction (X-axis direction) of the lower shell 101b. As a result, the replaceable battery 1 can easily slide along the guide. In addition, a metal component 105 is provided on the upper side of the bottom plate along the long side direction of the lower shell 101b. The metal component 105 is formed, for example, of aluminum or an alloy containing aluminum (i.e., a metal having aluminum as a main component).

[0032] Next, a rectangular parallelepiped cell stack 110 is placed on the upper side of the bottom plate formed by the lower casing 101b, near one of the side plates formed by the lower casing 101b (step S102). The cell stack 110 comprises a plurality of stacked battery cells and heat shields disposed between the cells. The cell stack 110 is bound into a rectangular parallelepiped shape using binding members 111, such as binding straps. Metal members 105, located above the bottom plate formed by the lower casing 101b and below the cell stack 110, serve to dissipate heat from the cell stack 110 outside the casing 100.

[0033] Subsequently, electronic devices such as a junction box 108 including relays and the like and a battery monitoring device 107 are further arranged on the upper side of the base plate formed by the lower housing 101b (step S103). The battery monitoring device 107 includes a voltage measuring device for measuring 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 the space between the cell stack 110 and the other side plate of the housing body 101, described later, in the area above the base plate formed by the lower housing 101b. This space is formed by arranging the cell stack 110 close to one of the side plates of the housing body 101. The junction box 108 is arranged in the space between the rear end of the cell stack 110 and the rear housing 103, described later.

[0034] In addition, the inner shell 102a of the front shell 102 is arranged at the front end of the lower shell 101b (shell body 101) (step S103). The rear shell 103 with the connector 104 is arranged at the rear end of the lower shell 101b (shell body 101) (step S103). The rear end of the battery stack 110 is connected to the rear shell 103 via the support rod 114. As a result, a space area sufficient to accommodate the junction box 108 is ensured between the rear end of the battery stack 110 and the rear shell 103. In addition, the front end of the battery stack 110 is connected to the front shell 102 with the handle 141, and the rear end of the battery stack 110 is connected to the rear shell 103 with the handle 131 via the support rod 114, thereby reducing the load applied to the shell body 101 when the operator grasps the handle 141 and the handle 131 to pick up the replaceable battery 1.

[0035] Thereafter, the upper shell 101a forming the top plate and the other side plate of the shell body 101 is arranged in a manner opposite to the lower shell 101b (step S104). The upper shell 101a is formed into an L-shape in the YZ cross-section and extends along the X-axis direction. The shell body 101 is formed into a square cylindrical shape by the upper shell 101a and the lower shell 101b. A space area 160 is provided above the battery cell stack 110 in the internal area of the shell body 101. The space area 160 is also used as a smoke exhaust area for allowing the gas generated in the battery cell stack 110 to escape. For example, the gas generated in the battery cell stack 110 is discharged from the space area 160 to the outside of the shell 100 via the safety valve 132.

[0036] In addition, the upper case 101a and the lower case 101b are fastened together by the fastening members 151 and 152 (step S104).

[0037] Thereafter, the outer housing 102b of the front housing 102 is placed at the front end of the housing body 101. Thus, the replaceable battery 1 is completed (step S105). The housing 102b has a lid shape and is installed so as to also cover the opening (open end) at the front end of the housing body 101 from the side. This prevents gas from leaking from the front housing 102 side where the operator is working before the gas is discharged from the safety valve 132.

[0038] Figure 7 FIG. 1 is a schematic cross-sectional view of the ZX plane of the replaceable battery 1. Figure 7 As shown, in the replaceable battery 1, the front end of the cell stack 110 is connected to the front housing 102 having a handle 141, and the rear end of the cell stack 110 is connected to the rear housing 103 having a handle 131 via support rods 114. This reduces the load applied to the housing body 101 when the operator grasps the handle 141 and handle 131 to pick up the replaceable battery 1. As a result, the replaceable battery 1 can reduce the thickness of the housing body 101, thereby achieving a lighter weight.

[0039] In addition, if Figure 7 As shown, in the cell stack 110 , a plurality of heat insulation plates 110 b are provided between the stacked plurality of battery cells 110 a . Figure 8This is a simplified exploded view of the battery cell stack 110. Each battery cell 110a has a rectangular stacking surface, and each heat insulating plate 110b has a rectangular stacking surface. Each heat insulating plate 110b is composed of, for example, a heat insulating material obtained by solidifying heat insulating powder such as silica, and a film covering the heat insulating material. Here, each heat insulating plate 110b is formed so as to cover the entire stacking surface of the battery cell 110a adjacent to the heat insulating plate. As a result, heat between the multiple battery cells 110a is not easily conducted, thereby suppressing the deterioration of each battery cell 110a caused by heat. In addition, each heat insulating plate 110b has a tapered edge portion 110c that avoids contact with the peripheral portion (edge) of the battery cell 110a adjacent to the heat insulating plate. This reduces the load applied from each heat insulating plate 110 b to the peripheral edge portion of the adjacent battery cell 110 a , thereby suppressing degradation of the peripheral edge portion of each battery cell 110 a due to the load.

[0040] Thus, in the replaceable battery 1 of the present disclosure, each heat shield 110b is formed to cover the entire stacked surface of the battery cells 110a adjacent to that heat shield. This prevents heat from being transferred between the multiple battery cells 110a, thereby suppressing thermal degradation of the battery cells 110a. Furthermore, each heat shield 110b has a tapered edge 110c that prevents contact with the peripheral edge (edge) of the battery cell 110a adjacent to that heat shield. This reduces the load applied from each heat shield 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 of the present disclosure can suppress load-induced degradation of the peripheral edge of the multiple battery cells 110a, and can also suppress thermal degradation of the multiple battery cells 110a.

[0041] The present invention is not limited to the above-described embodiment, and can be appropriately modified without departing from the spirit and scope of the invention.

[0042] This disclosure describes a case in which each heat shield plate in a cell stack mounted on a replaceable battery 1 is formed to cover the entire stacked surface of the battery cells adjacent to the heat shield plate and has a tapered edge portion that prevents contact with the edge of the battery cells adjacent to the heat shield plate. However, the present disclosure is not limited to this. The cell stack disclosed herein can be applied to various power storage devices other than replaceable batteries.

[0043] Based on the above disclosure, the embodiments of the present disclosure can obviously be changed in various ways. These changes should not be regarded as departing from the spirit and scope of the present disclosure, and for those skilled in the art, all these changes are obviously included in the scope of the technical solution.

Claims

1. A power storage device comprising: Multiple battery cells stacked together; a plurality of heat insulation plates disposed between the plurality of battery cells; and a housing for accommodating a cell stack having the plurality of battery cells and the plurality of thermal insulation plates, in, Each of the heat shielding plates is formed to cover the entire surface of the stacked battery cells adjacent to the heat shielding plate and has a tapered edge portion that avoids contact with the edge of the battery cells adjacent to the heat shielding plate.

2. The power storage device according to claim 1, wherein Each of the heat insulation panels has: Thermal insulation material, which is formed by solidifying thermal insulation powder; and Membrane, covering thermal insulation material.

3. The power storage device according to claim 1, wherein The thermal insulation board comprises silicon dioxide.

4. The power storage device according to claim 1, wherein The plurality of battery cells have a rectangular stacking surface, The plurality of heat insulation panels have a rectangular stacking surface.

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