Power storage module

Abstract

The present invention relates to a storage module. A stacked body is stacked with a plurality of storage cells (100). A resin plate (400) is placed on the stacked body. A flexible printed substrate (510) is placed on the resin plate (400) and has a circuit electrically connected to the plurality of storage cells (100). A thermistor element (550) is arranged on the circuit and contacts one of the plurality of storage cells (100) to detect the temperature of the storage cell (100). A cover component (700) is arranged on the resin plate (400) and covers the flexible printed substrate (510). An elastic body (740) is located between the cover component (700) and the thermistor element (550) and presses the thermistor element (550) against the storage cell (100). The cover component (700) includes a protrusion (730) protruding toward the resin plate (400) side. The elastic body (740) is arranged on the protrusion (730).

Description

Technical Field

[0001] The present technology relates to a power storage module. Background Art

[0002] As an existing document that discloses the structure of a power storage module, there is International Publication No. 2019 / 073857. The power storage module described in International Publication No. 2019 / 073857 includes a detection object as a power storage element and a sensor unit. The sensor unit includes a conductive path constituent body, a sensor element, a base portion, and a force-applying component. The conductive path constituent body is arranged on the detection object. The sensor element is connected to the conductive path on the surface of the conductive path constituent body. The base portion is arranged on the conductive path constituent body in a manner covering the sensor element. The force-applying component applies force to the base portion toward the detection object, thereby causing the conductive path constituent body to contact the detection object. A resin protective portion covering the sensor element is provided between the base portion and the sensor element. Summary of the invention

[0003] In the power storage module described in International Publication No. 2019 / 073857, the structure of the sensor unit is complex. When the temperature of the power storage unit is detected by pressing the power storage unit against the thermistor element using a force application member, the temperature detection accuracy may be reduced due to heat transfer through the force application member and the thermistor element.

[0004] The present technology has been made to solve the above-mentioned problems, and an object of the present technology is to provide a power storage module capable of suppressing a decrease in the temperature detection accuracy of a thermistor element with a simple structure.

[0005] The power storage module based on the present technology comprises a stack, a resin plate, a flexible printed substrate, a thermistor element, a resin cover component, and an elastic body. In the stack, a plurality of power storage cells are stacked. The resin plate is mounted on the stack. The flexible printed substrate is mounted on the resin plate and has a circuit electrically connected to the plurality of power storage cells. The thermistor element is arranged on the above-mentioned circuit, contacts one of the plurality of power storage cells and detects the temperature of the power storage cell. The cover component is arranged on the resin plate and covers the flexible printed substrate. The elastic body is located between the cover component and the thermistor element, pressing the thermistor element against the power storage cell. The cover component includes a protrusion protruding toward the resin plate side. The elastic body is arranged on the protrusion.

[0006] The foregoing and other objects, features, aspects and advantages of the present invention will become more apparent from the following detailed description of the present invention when taken in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] Figure 1 It is a diagram showing the basic structure of a battery pack.

[0008] Figure 2 Yes means Figure 1 A diagram of battery cells and end plates in a battery pack is shown.

[0009] Figure 3 Yes means Figure 1 Diagram of battery cells in a battery pack shown.

[0010] Figure 4 This is a perspective view showing a state where a wiring module is installed on a battery pack.

[0011] Figure 5 This is a schematic top view of a wiring module mounted on a battery pack.

[0012] Figure 6 This is a schematic plan view of a cover member covering the wiring module.

[0013] Figure 7 This is a cross-sectional view showing a state immediately before the elastic body located between the cover member and the thermistor element presses the thermistor element against the battery cell.

[0014] Figure 8 It is a perspective view showing a state in which the opening and closing window provided in the cover member is opened. DETAILED DESCRIPTION

[0015] Hereinafter, embodiments of the present technology will be described. It should be noted that the same reference numerals are given to the same or corresponding parts, and the description thereof may not be repeated.

[0016] It should be noted that, in the embodiments described below, when the number, amount, etc. are mentioned, the scope of the present technology is not necessarily limited to the number, amount, etc., unless otherwise specified. In addition, in the following embodiments, each component is not necessarily essential to the present technology, except for the case of special description.

[0017] It should be noted that in this specification, the descriptions of "having", "including", and "having" are open-ended. That is, when a certain structure is included, other structures other than the structure may be included or not. In addition, the present technology is not limited to the technology that must achieve all the effects mentioned in this embodiment.

[0018] In this specification, "battery" is not limited to lithium-ion batteries, and may include other batteries such as nickel-metal hydride batteries. In this specification, "electrode" may be collectively referred to as positive electrode and negative electrode. In addition, "electrode plate" may be collectively referred to as positive electrode plate and negative electrode plate.

[0019] In this specification, the “power storage unit” or “power storage module” is not limited to a battery cell or a battery module, and may include a capacitor cell or a capacitor module.

[0020] Figure 1 1 is a diagram showing a basic structure of the battery pack 1 . Figure 2 The diagram shows a battery cell 100 and an end plate 200 included in the battery pack 1 .

[0021] like Figure 1 , Figure 2 As shown, a battery pack 1 as an example of a “power storage module” includes a battery cell 100 , an end plate 200 , and a restraint member 300 .

[0022] The plurality of battery cells 100 are arranged in a manner arranged along the Y-axis direction (arrangement direction). Thus, a stack of battery cells 100 is formed. A separator not shown is sandwiched between the plurality of battery cells 100. The plurality of battery cells 100 sandwiched by the two end plates 200 are pressed by the end plates 200 and constrained between the two end plates 200.

[0023] The end plates 200 are disposed at both ends of the battery pack 1 in the Y-axis direction. The end plates 200 are fixed to a base such as a case that accommodates the battery pack 1. Step portions 210 are formed at both ends of the end plates 200 in the X-axis direction.

[0024] The restraining member 300 connects the two end plates 200 to each other. The restraining member 300 is attached to the step portions 210 formed on the two end plates 200, respectively.

[0025] The restraining member 300 is engaged with the end plate 200 while a compressive force in the Y-axis direction is applied to the stack of the plurality of battery cells 100 and the end plate 200, and then the compressive force is released, so that a tensile force acts on the restraining member 300 connecting the two end plates 200. As a reaction, the restraining member 300 presses the two end plates 200 in a direction toward each other.

[0026] The restraining member 300 includes a first member 310 and a second member 320. The first member 310 and the second member 320 are joined to each other by, for example, butt welding. The front end surface of the second member 320 formed by folding back abuts against the step portion 210 of the end plate 200 in the Y-axis direction.

[0027] Figure 3 1 is a diagram showing a battery cell 100 in a battery pack 1. Figure 3 As shown, the battery cell 100 includes an electrode terminal 110 , a frame 120 , and a gas exhaust valve 130 .

[0028] The electrode terminal 110 includes a positive terminal 111 and a negative terminal 112. The electrode terminal 110 is formed on the frame 120. The frame 120 is formed in a substantially rectangular parallelepiped shape. The frame 120 contains an electrode body and an electrolyte solution (not shown). The gas discharge valve 130 breaks when the pressure in the frame 120 becomes greater than a predetermined value. As a result, the gas in the frame 120 is discharged to the outside of the frame 120.

[0029] Figure 4 1 is a perspective view showing a state where a wiring module is provided on the battery pack 1. Figure 4 As shown, a plate member 400 is placed on the battery pack 1, and a wiring member 500 is provided on the plate member 400. The wiring member 500 can be electrically connected to an external device via a connector 600. A cover member 700 is provided on the plate member 400 so as to cover the wiring member 500.

[0030] Figure 5 is a schematic top view of a wiring module mounted on the battery pack 1. Figure 5 As shown, the wiring module includes a board component 400 , a wiring component 500 , and a connector 600 .

[0031] The plate member 400 (busbar plate) is a resin plate having insulation and heat resistance. The plate member 400 has a bottom surface portion 400A and a side surface portion 400B formed so as to stand up from the bottom surface portion 400A in the Z-axis direction.

[0032] The plate member 400 includes a wall portion 410 , openings 420 , 430 , and protrusions 440 , 450 .

[0033] The wall portion 410 is formed so as to stand up in the Z-axis direction from the bottom surface portion 400A of the plate member 400. The wall portion 410 includes a first wall portion 411 formed on the center side in the X-axis direction and a second wall portion 412 provided on the outside in the X-axis direction parallel to the first wall portion 411. The first wall portion 411 and the second wall portion 412 are formed so as to extend intermittently in the Y-axis direction.

[0034] The first wall 411 and the second wall 412 may function as a protective wall that secures a passage for discharging gas exhausted from the frame 120 of the battery cell 100 to the outside of the battery pack and prevents sparks generated in the plate member 400 from being directly exposed to the outside.

[0035] The opening 420 is located above a position between the electrode terminal 110 and the gas discharge valve 130 in the battery cell 100 located at the end in the Y-axis direction among the stacked battery cells 100. The opening 430 is located above the electrode terminal 110 of the battery cell 100.

[0036] The protrusion 440 (convex portion) passes through the wiring member 500 in the vicinity of the connector 600. Thus, the connector 600 is positioned.

[0037] A plurality of protrusions 450 are formed so as to be aligned in the Y-axis direction. The plurality of protrusions 450 penetrate the wiring member 500. The number of protrusions 450 can be arbitrarily changed.

[0038] The wiring component 500 includes a flexible printed substrate 510 , a displacement absorbing portion 520 , a bus bar bonding portion 530 , a long hole 540 , and a thermistor element 550 .

[0039] The flexible printed circuit board 510 is a substrate having a circuit formed on a base material composed of an insulating base film and a conductive metal foil. The base film is composed of, for example, polyimide. The conductive metal foil is composed of, for example, copper foil. The flexible printed circuit board 510 has flexibility and has the characteristic of maintaining its electrical characteristics even when deformed.

[0040] The displacement absorbing portion 520 forms a portion of the flexible printed substrate 510 into a substantially U-shape, which is easily deformed. The displacement absorbing portion 520 is connected to the bus bar joint portion 530. The bus bar joint portion 530 is joined to the bus bar 100A that connects the electrode terminals 110 of the plurality of battery cells 100. Thus, the circuit provided on the flexible printed substrate 510 is electrically connected to the battery pack 1. The displacement of the bus bar joint portion 530 (in the X-axis direction, the Y-axis direction, and the Z-axis direction) can be absorbed by the displacement absorbing portion 520.

[0041] A plurality of long holes 540 are formed in a manner arranged in the Y-axis direction. The number of long holes 540 can be changed arbitrarily. In each of the plurality of long holes 540, the plurality of protrusions 450 are inserted one by one. As the distance from the connector 600 increases, the length of the long hole 540 in the Y-axis direction becomes longer. Thus, it is easy to position the wiring component 500 and the connector 600 when they are placed on the plate component 400.

[0042] The thermistor element 550 is provided on the circuit of the flexible printed substrate 510. The thermistor element 550 is arranged on one of the battery cells 100 located at the end in the Y-axis direction among the plurality of battery cells 100 in the battery pack 1. The thermistor element 550 contacts the one battery cell 100 through the opening 420 to detect the temperature of the battery cell 100. Thus, the thermistor element 550 detects the temperature of the battery cell 100 with the lowest temperature in the battery pack 1. It should be noted that the temperature of the battery cell 100 with the highest temperature in the battery pack 1 may be detected by the thermistor element 550, and a plurality of thermistor elements 550 may be used to detect the temperatures of a plurality of battery cells 100.

[0043] The connector 600 is fixed to the flexible printed circuit board 510. The circuit in the flexible printed circuit board 510 can be electrically connected to an external electric device via the connector 600.

[0044] Figure 6 Yes Cover Figure 5 The schematic top view of the cover member 700 (bus bar cover) of the wiring module is shown. The cover member 700 is provided on the plate member 400 and covers the flexible printed circuit board 510.

[0045] like Figure 6 As shown, the cover member 700 includes a main body 710, a cylindrical protrusion 720, a protruding portion 730, and an opening and closing window 750. The cylindrical protrusion 720 protrudes toward the flexible printed substrate 510 on the plate member 400.

[0046] The protrusion 730 protrudes from the main body 710 toward the plate member 400. The protrusion 730 has a bottomed cylindrical shape that bulges out from the main body 710. The protrusion 730 is formed at a position aligned with the thermistor element 550 in the Z-axis direction.

[0047] An elastic body 740 is disposed on the protrusion 730. The elastic body 740 is bonded to the protrusion 730. The elastic body 740 is, for example, a resin foam such as a sponge. It should be noted that the elastic body 740 can be elastically deformed at least in the Z-axis direction, and can be other resin elastic bodies such as rubber or resin springs, or metal elastic bodies.

[0048] The protrusion 730 has a through hole 731 extending from the side opposite to the side where the elastic body 740 is disposed in the Z-axis direction to a position reaching the elastic body 740. Thus, the elastic body 740 can be visually recognized through the through hole 731 from the outside of the cover member 700.

[0049] The colors of the surfaces of the elastic body 740 and the cover member 700 are different from each other. The color of the surface of the elastic body 740 is, for example, black. The color of the surface of the cover member 700 is, for example, milky white. Thus, when visually checking from the outside of the cover member 700 through the through hole 731, it is possible to check whether the elastic body 740 is arranged on the protrusion 730 by checking whether the black part of the elastic body 740 corresponding to the shape of the through hole 731 can be checked against the milky white background.

[0050] The opening and closing window 750 is provided adjacent to the protrusion 730. The opening and closing window 750 is provided so as to be able to open and close an opening formed at a corner of the main body 710 by a hinge (not shown). By opening the opening and closing window 750, the periphery of the elastic body 740 can be visually confirmed from the outside of the cover member 700.

[0051] Figure 72 is a cross-sectional view showing a state in which the elastic body between the cover member and the thermistor element is about to press the thermistor element against the battery cell. Figure 7 As shown, a plate-like member 560 is provided on the side opposite to the thermistor element side of the flexible printed substrate 510. The plate-like member 560 is provided to improve the thermal conductivity between the thermistor element 550 and the battery cell 100 and to facilitate the mounting of the thermistor element 550 on the flexible printed substrate 510. The plate-like member 560 is formed of, for example, aluminum.

[0052] The elastic body 740 is located between the cover member 700 and the thermistor element 550 in the Z-axis direction, and presses the thermistor element 550 against the battery cell 100. Specifically, the elastic body 740 uses the rebound force when it is sandwiched between the protrusion 730 and the thermistor element 550 and elastically deformed, and presses the flexible printed circuit board 510 and the plate-shaped member 560 together with the thermistor element 550 against the battery cell 100. As a result, the thermistor element 550 is closely attached to the battery cell 100 via the flexible printed circuit board 510 and the plate-shaped member 560.

[0053] In the state before the elastic body 740 is sandwiched between the cover member 700 and the thermistor element 550, the ratio of the minimum width dimension L2 of the elastic body 740 in the direction perpendicular to the Z-axis direction to the height dimension L1 of the elastic body 740 in the direction (Z-axis direction) sandwiched between the cover member 700 and the thermistor element 550 is greater than 1. Thus, when the elastic body 740 is sandwiched between the protrusion 730 and the thermistor element 550, the elastic body 740 can be made less likely to be buckled.

[0054] Figure 8 1 is a perspective view showing a state where the opening and closing window provided in the cover member is opened. Figure 8 As shown, when the opening and closing window 750 is opened, the contact state between the elastic body 740 and the thermistor element 550 can be visually confirmed. Thus, it can be confirmed whether the elastic body 740 presses the thermistor element 550 against the battery cell 100.

[0055] In the power storage module of the present embodiment, by using a simple structure in which the thermistor element 550 is pressed against the battery cell 100 by using the resin elastic body 740 arranged on the protrusion 730 provided on the resin cover member 700, the thermistor element 550 can be closely attached to the battery cell 100 via the flexible printed substrate 510 while ensuring that the heat transfer distance between the thermistor element 550 and the main body 710 of the cover member 700 is long and the resin elastic body 740 with a low thermal conductivity is interposed between the thermistor element 550 and the cover member 700. Therefore, it is possible to suppress a reduction in the temperature detection accuracy of the thermistor element 550 due to heat transfer through the elastic body 740 and the thermistor element 550.

[0056] In the storage battery module of the present embodiment, in the state before being sandwiched between the cover part 700 and the thermistor element 550, by making the ratio of the minimum width dimension L2 of the elastic body 740 in the direction perpendicular to the sandwiched direction to the height dimension L1 of the elastic body 740 in the direction sandwiched between the cover part 700 and the thermistor element 550 be greater than 1, it is possible to make it difficult for the elastic body 740 to be buckled when the elastic body 740 is compressed in the Z-axis direction and it is difficult for the elastic body 740 to be tilted in the X-axis direction and the Y-axis direction. Therefore, the thermistor element 550 can be stably pressed against the battery cell 100 by the elastic body 740.

[0057] In the storage module of the present embodiment, an opening and closing window 750 is provided in the cover part 700. When the opening and closing window 750 is open, the contact state between the elastomer 740 and the thermistor element 550 can be visually confirmed from the outside of the cover part 700. Therefore, after the cover part 700 is assembled to the plate part 400, it can be confirmed whether the elastomer 740 presses the thermistor element 550 against the battery cell 100.

[0058] In the storage battery module of this embodiment, a through hole 731 is formed in the protrusion 730, which penetrates from the opposite side of the side where the elastic body 740 is arranged to the position where the elastic body 740 is reached, so that it can be confirmed whether the elastic body 740 is arranged on the protrusion 730 by visually observing the through hole 731 from the outside of the cover part 700.

[0059] In the power storage module of this embodiment, the surfaces of the elastic body 740 and the cover member 700 have different colors, so that it is easy to check whether the elastic body 740 is disposed on the protrusion 730 by visually observing the through hole 731 from the outside of the cover member 700 .

[0060] Although the embodiments of the present invention have been described, the embodiments disclosed this time should be understood to be illustrative in all aspects and not restrictive. The scope of the present invention is indicated by the claims, and it is intended to include all modifications within the meaning and scope equivalent to the claims.

Claims

1. A power storage module, wherein: The power storage module comprises: a stacked body in which a plurality of power storage units are stacked; a resin plate placed on the laminate; a flexible printed substrate mounted on the resin plate and having a circuit electrically connected to the plurality of power storage cells; a thermistor element, the thermistor element being disposed on the circuit and in contact with one of the plurality of storage cells to detect a temperature of the storage cell; a resin cover member, the cover member being disposed on the resin plate and covering the flexible printed circuit board; as well as an elastic body, the elastic body being located between the cover member and the thermistor element and pressing the thermistor element against the power storage unit, The cover member includes a protrusion protruding toward the resin plate side, The elastic body is arranged on the protruding portion, The protruding portion has a through hole formed therein, the through hole penetrating from a side opposite to a side where the elastic body is arranged to a position reaching the elastic body.

2. The power storage module according to claim 1, wherein: In a state before being sandwiched between the cover component and the thermistor element, a ratio of a minimum width dimension of the elastic body in a direction perpendicular to the sandwiched direction to a height dimension of the elastic body in the direction sandwiched between the cover component and the thermistor element is greater than 1.

3. The power storage module according to claim 1 or 2, wherein: The cover member is provided with an opening and closing window, When the opening and closing window is opened, the contact state between the elastic body and the thermistor element can be visually confirmed.

4. The power storage module according to claim 1 or 2, wherein: The elastic body and the cover member have surfaces with different colors.

5. The power storage module according to claim 3, wherein: The elastic body and the cover member have surfaces with different colors.

Images