Battery case

Abstract

To provide a battery case capable of preventing the sheathing of a wire or a wire harness from being damaged by the heat of exhaust gas from a battery stack.SOLUTION: The battery case includes a battery cover, wires, and a pressure regulating valve. The battery cover is formed in a box shape. The wire connects the outside of the battery cover and the internal components of the battery cover including the battery stack. The wire is covered by a covering sheathing material. The pressure-regulating valve is configured so as to, when the internal pressure of the battery cover increases, open to release the gas inside the battery cover from the inside of the battery cover to the outside. The wire is provided to pass through the first side of the battery cover. The pressure regulating valve is placed on the second side opposite to the first side.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a battery case that houses a battery stack. [Background technology]

[0002] International Publication No. 2020 / 189161 discloses an electricity storage device. This conventional electricity storage device includes an exterior body that houses a battery stack, a ventilation chamber provided in a lid of the exterior body, and an exhaust port provided in the ventilation chamber. The ventilation chamber is formed to protrude outside the lid of the exterior body, and a ventilation hole and an exhaust section are formed in a portion of the lid that forms the inner wall of the ventilation chamber. The ventilation hole and the exhaust section are configured to exchange gas between the inside and outside of the exterior body.

[0003] The opening of the ventilation hole located on the inner wall side of the ventilation chamber is covered with a waterproof membrane. Under normal conditions, gas passes through this waterproof membrane, thereby achieving pressure equilibrium inside and outside the exterior body. Meanwhile, the exhaust section has a valve member that normally closes the exhaust section. This valve member is configured to open the exhaust section when gas is exhausted from the battery stack and the gas pressure on the battery stack side increases. When the exhaust section is open, exhaust gas from the battery stack flows into the ventilation chamber, thereby achieving pressure equilibrium inside the exterior body.

[0004] The vent hole is also formed on a path different from the path through which exhaust gas from the battery stack flows. Therefore, in a conventional energy storage device, exhaust gas from the battery stack can be prevented from flowing through the vent hole. Therefore, damage to the waterproof film provided at the opening of the vent hole can be prevented when gas is exhausted from the battery stack. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] International Publication No. 2020 / 189161 Summary of the Invention [Problem to be solved by the invention]

[0006] Conventional energy storage devices have positive and negative terminals attached to a lid, and bus bars are connected to these terminals, through which the battery stack is charged from an external power source or discharged from the battery stack to an external load.

[0007] Although WO 2020 / 189161 does not disclose details, wires are generally provided between the busbar and the external power supply or external load, and these wires are covered with a covering material. In the case of a wire harness, the wires constituting the wire harness are each covered with a covering material, or the entire wire harness is covered with a single covering material.

[0008] Conventional power storage devices focus on the flow of exhaust gas from the battery stack within the ventilation chamber, but do not consider the flow outside the ventilation chamber (i.e., outside the power storage device). However, the exhaust gas from the battery stack is likely to be hot. Therefore, if the exhaust gas comes into contact with wires or wiring harnesses located outside the ventilation chamber, the heat may damage the coating material of the wires. Therefore, conventional power storage devices have room for improvement.

[0009] One object of the present disclosure is to provide a technology that can prevent damage to the coating material of the wires or wire harnesses caused by the heat of exhaust gas from the battery stack. [Means for solving the problem]

[0010] A first aspect of the present disclosure is a battery case that houses a battery stack, and has the following features. The battery case includes a battery cover, a wire, and a pressure regulation valve. The battery cover is formed in a box shape. The wire connects the outside of the battery cover to components inside the battery cover, including the battery stack. The wire is covered with a coating material. The pressure regulation valve opens when the internal pressure of the battery cover increases, releasing gas inside the battery cover from the inside to the outside. The wire is provided to pass through a first side surface of the battery cover. The pressure regulating valve is provided on a second side surface opposite to the first side surface.

[0011] The second aspect of the present disclosure further includes the following features in addition to the first aspect. The first side surface is located at one end of the battery stack in the longitudinal direction, and the second side surface is located at the other end of the battery stack in the longitudinal direction.

[0012] A third aspect of the present disclosure is the first or second aspect further characterized by the following. The internal components include a junction block to which the wires are connected inside the battery cover. Each of the plurality of wires is covered with a covering material. The junction block is provided on the first side surface side.

[0013] A fourth aspect of the present disclosure further includes the following features in addition to the third aspect. The battery case further includes a breather membrane, which is provided on the first side surface and provides ventilation for the battery cover. The internal components include first and second plate members, the first plate member supporting the battery stack, and the second plate member supporting the junction block. In the arrangement direction of the first and second plate members, the pressure adjustment valve is provided on the first plate member side, and the breathing membrane is provided on the second plate member side. [Effects of the Invention]

[0014] According to a first aspect, a wire covered with a coating material is provided to penetrate a first side surface of the battery cover, and a pressure regulating valve is provided on a second side surface opposite the first side surface. The pressure regulating valve opens when the internal pressure of the battery cover rises, for example, when gas is generated from the battery stack. In this way, exhaust gas from the battery stack is discharged from the second side surface, minimizing the time that the coating material of the wire provided to penetrate the first side surface is exposed to the gas. Therefore, it is possible to prevent damage to the coating material of the wire due to the heat of the gas when the gas is generated from the battery stack.

[0015] According to the second aspect, the first side surface is located at one longitudinal end of the battery stack, and the second side surface is located at the other longitudinal end, which minimizes the time that the wire coating material is exposed to exhaust gas from the battery stack, thereby enhancing the effect of the first aspect.

[0016] According to the third aspect, the junction block to which the wires are connected is provided on the first side surface, which minimizes the time that the covering materials of the wires are exposed to exhaust gas from the battery stack, thereby preventing damage to the covering materials of the wires connected to the junction block due to heat from the gas generated by the battery stack.

[0017] According to the fourth aspect, in the arrangement direction of the first and second plates, the pressure adjustment valve is provided on the first plate side and the breathing membrane is provided on the second plate side, which makes it possible to minimize the time that the breathing membrane is exposed to exhaust gas from the battery stack, thereby making it possible to prevent the breathing membrane from being damaged by the heat of the gas when the gas is generated from the battery stack. [Brief explanation of the drawings]

[0018] [Figure 1] FIG. 2 is a perspective view showing an example of the configuration of a battery case according to an embodiment. [Figure 2] 2 is a diagram illustrating the flow of gas generated from the battery stack in the battery case shown in FIG. 1. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0019] Hereinafter, a battery case according to an embodiment will be described with reference to the drawings. In each drawing, the same or corresponding parts are designated by the same reference numerals, and the description thereof will be simplified or omitted.

[0020] 1. Example of overall battery case configuration The battery case according to the embodiment is applied to a storage battery system in a small facility such as a general household or a food and beverage store. The battery case according to the embodiment is installed adjacent to the facility and supplies power to various electrical appliances or receives power from an external power source. FIG. 1 is a perspective view showing an example of the configuration of a battery case according to the embodiment. Note that the positive direction of the x-axis shown in FIG. 1 indicates, for example, the front of the battery case, the positive direction of the y-axis indicates, for example, the left of the battery case, and the positive direction of the z-axis indicates, for example, the top of the battery case. The example of the positional relationship between the positive directions of the x-axis, y-axis, and z-axis and the battery case is the same in other figures.

[0021] In the example shown in FIG. 1, the battery case is equipped with a battery cover 11. The battery cover 11 is formed in a box shape. The bottom of the battery cover 11 is open, and the outer edge of this bottom protrudes around the battery cover 11 like a canopy. This outer edge is mechanically joined (bolted) to a bottom plate material 12. The bottom plate material 12 is made of, for example, a general-purpose flat bar (flat steel). The bottom of the battery cover 11 is sealed by this bottom plate material 12.

[0022] In the example shown in FIG. 1, for ease of explanation, the internal structure of the battery case is depicted as seen through the battery cover 11. The interior of the battery case is composed of three levels, with the first level (lower level) and the second level (middle level) separated by a plate member 21, and the second level (middle level) and the third level (upper level) separated by a plate member 31. The plates 21 and 31 are composed of, for example, general-purpose flat bars. The plate member 21 is supported by supports 22a to 22e. The plate member 31 is supported by supports 32a to 32d. The plate member 21 corresponds to the "first plate member" in this disclosure, and the plate member 31 corresponds to the "second plate member" in this disclosure. The plates 21 and 31 are examples of "components inside the battery cover" in this disclosure.

[0023] The second stage houses a battery stack FC, which is made up of multiple stacked cells. The longitudinal direction of the battery stack FC coincides with the x-axis direction (i.e., the front-to-rear direction). A battery stack having the same configuration as the battery stack FC is also housed in the first stage. This first stage battery stack is arranged parallel to the second stage battery stack (i.e., the battery stack FC). However, this first stage battery stack is hidden behind the L-shaped plate member 51 shown in FIG. 1.

[0024] The third tier houses electronic components for controlling the charging and discharging of the first and second tier battery stacks. Examples of these electronic components include a battery ECU (Electric Control Unit) and a voltage sensor. The battery ECU is an electronic component for controlling the charging and discharging of the battery stack, and is housed in component case 34. The voltage sensor is, for example, a device for detecting the voltage of each cell constituting the battery stack, and is housed in component case 35. Component cases 34 and 35 are made of, for example, a resin housing. Component cases 34 and 35 are stacked in the z-axis direction (i.e., vertical direction), and in the example shown in FIG. 1, component case 35 is provided above component case 34.

[0025] The third tier also houses a junction block 33. The junction block 33 is located in front of the component cases 34 and 35 (in front of the battery case). Wire harnesses WH1 to WH3 are connected to the junction block 33 and are drawn into the battery case from the outside. These wire harnesses are arranged to pass through the first side surface 11a of the battery case 11. In the example shown in FIG. 1, the wire harness WH1 includes a communication wire and is connected to both the junction block 33 and the battery ECU. The wire harness WH2 includes a high-voltage positive wire and is connected to the junction block 33. The wire harness WH3 includes a high-voltage negative wire and is connected to the junction block 33. The wires included in the wire harnesses WH1 to WH3 are an example of the "wire" in the present disclosure. The junction block 33 is an example of the "component inside the battery cover" in the present disclosure.

[0026] The junction block 33 is provided with a plurality of relays. The plurality of relays are connected to any of the various electronic components inside the battery case. The plurality of relays and the various electronic components are also connected by wire harnesses. The wire harnesses WH4, WH5, and WH6 shown in FIG. 1 are examples of such wire harnesses. The wire harnesses WH4, WH5, and WH6 include communication wires. The wires included in the wire harnesses WH1 to WH6 are each covered with a resin coating material. The wires included in the wire harnesses WH1 to WH6 are an example of the "plurality of wires" in the present disclosure.

[0027] In the example shown in FIG. 1, the battery case has multiple support members 41 (support members 41a to 41j). These support members 41 are provided around the battery stack FC, and each support member 41 extends in the z-axis direction (i.e., vertical direction). Each support member 41 is made of, for example, a general-purpose aluminum extrusion. Each tip of the support member 41 faces the inner surface of the battery cover 11. Meanwhile, each base end of the support member 41 faces the upper surface of the bottom plate material 12. The support members 41a, 41c, 41e, 41g, and 41i are lined up on the left side of the battery stack FC. Meanwhile, the support members 41b, 41d, 41f, 41h, and 41j are lined up on the right side of the battery stack FC.

[0028] The support members 41a and 41b form a pair on the left and right sides of the battery stack FC. Similarly, the support members 41c and 41d form a pair, the support members 41e and 41f form a pair, the support members 41g and 41h form a pair, and the support members 41i and 41j form a pair. The total number of support members 41 is not limited to the number (10) shown in FIG. 1. The total number of support members 41 can be changed as desired, as long as it includes at least the support members 41 corresponding to the four corners of the battery stack FC (i.e., the support members 41a, 41b, 41i, and 41j).

[0029] A ventilation member 62 is provided on the first side surface 11a above the aggregation plate 61. The ventilation member 62 has a breathable membrane 62a. The breathable membrane 62a is located above the plate material 31. The breathable membrane 62a is made of a waterproof, breathable material that allows gas to pass through but prevents liquid from passing through. For example, if a difference in pressure occurs between the inside and outside of the battery cover 11 due to a change in the ambient temperature of the battery case, gas is exchanged via the breathable membrane 62a, thereby achieving pressure equilibrium between the inside and outside of the battery cover 11.

[0030] A pressure regulation valve 71 is provided on the second side surface 11b opposite the first side surface 11a. In the example shown in FIG. 1, the pressure regulation valve 71 is provided between the plate material 31 and the bottom plate material 12. The pressure regulation valve 71 is composed of a normally closed valve member and opens when the internal pressure of the battery cover 11 increases. For example, if a short circuit occurs between electronic components due to foreign matter mixed inside the battery cover 11 or if overcharging occurs, the cells will heat up and emit high-temperature gas. In such cases, the pressure regulation valve 71 quickly opens, thereby discharging the gas inside the battery cover 11 to the outside.

[0031] The arrows in Figure 2 indicate the direction of gas flow inside the battery cover 11 that occurs when the pressure regulation valve 71 is opened. When the pressure regulation valve 71 is opened, high-temperature gas is discharged from the pressure regulation valve 71. When the high-temperature gas is discharged, the internal pressure of the battery cover 11 decreases, and the pressure regulation valve 71 closes. Thereafter, gas is exchanged via the breathing membrane 62a as usual. For example, when the gas temperature inside the battery cover 11 is higher than that outside due to the generation of high-temperature gas, the gas that flows in through the breathing membrane 62a cools components such as the junction block 36.

[0032] 2.Effects According to the battery case according to the embodiment described above, the wire harnesses WH1 to WH3 are drawn into the battery case 11 from the outside to the inside by passing through the first side surface 11a, and the pressure adjustment valve 71 is provided on the second side surface 11b. This makes it possible to minimize the time that the covering material of the wire harnesses WH1 to WH3 is exposed to high-temperature gas ejected from the cells when the internal pressure of the battery cover 11 rises, causing the pressure adjustment valve 71 to open. This makes it possible to prevent the covering material of the wire harnesses WH1 to WH3 from being damaged by the heat of this high-temperature gas, resulting in the exposure of conductive parts.

[0033] Furthermore, in the battery case according to the embodiment, the junction block 36 is located close to the first side surface 11a. This minimizes the time that the covering material of the wire harnesses (i.e., wire harnesses WH4 to WH6) extending from the junction block 36 to the various electronic components is exposed to the high-temperature gas emitted from the cells. This prevents the covering material of the wire harnesses WH4 to WH6 from being damaged by the heat of the high-temperature gas, thereby preventing the conductive parts from being exposed.

[0034] Furthermore, in the battery case according to the embodiment, the pressure adjustment valve 71 is provided between the plate material 31 and the bottom plate material 12 (i.e., at a lower position), while the air intake membrane 62a is provided at a position above the plate material 21. This makes it possible to minimize the time that the air intake membrane 62a is exposed to the high-temperature gas ejected from the cell. This makes it possible to prevent damage to the air intake membrane 62a caused by the heat of this high-temperature gas. [Explanation of symbols]

[0035] 11 Battery cover 12 Bottom plate material 21, 31 Plate material 22a~22d, 32a~32d Support material 33 Junction Block 34, 35, 36 Parts case 41a~41j Support members 51 L-shaped plate material 61 Aggregate board 62 Ventilation components 62a Respiratory membrane 71 Pressure Regulating Valve FC battery stack WH1~WH6 Wire harness

Claims

1. A battery case that houses a battery stack, a box-shaped battery cover; a wire connecting the exterior of the battery cover to components inside the battery cover, including the battery stack, the wire being covered with a coating material; a pressure regulating valve that opens when the internal pressure of the battery cover increases to release gas inside the battery cover from the inside to the outside of the battery cover; Equipped with The wire is provided to pass through a first side surface of the battery cover, the pressure regulating valve is provided on a second side surface opposite to the first side surface, the internal components include a junction block to which a plurality of wires are connected inside the battery cover; Each of the plurality of wires is covered with a coating material; the junction block is provided on the first side surface side, a breathing membrane provided on the first side surface for ventilating the battery cover; the internal components include a first plate member that supports the battery stack and a second plate member that is provided parallel to the first plate member and supports the junction block; In the arrangement direction of the first and second plate members, the pressure adjustment valve is provided on the first plate member side, and the breathing membrane is provided on the second plate member side. A battery case characterized by:

2. The first side surface is located at one end of the battery stack in the longitudinal direction, and the second side surface is located at the other end of the battery stack in the longitudinal direction.

2. The battery case according to claim 1, wherein the battery case is made of a polycarbonate material.

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