Vehicle battery pack

Abstract

In vehicle battery packs, the aim is to mitigate the rise in internal pressure and prevent the inflow of air and water. [Solution] The housing 12 houses the battery 15. The unfolding section 13 is connected to the connection port 21 of the housing 12 and unfolds to form a closed space when the internal pressure of the housing 12 increases.

Description

Technical Field

[0005] , , ,

[0006] , ,

[0001] The present invention relates to a vehicle battery pack.

Background Art

[0002] The pressure release valve of the battery pack disclosed in Patent Document 1 has a structure in which when a large amount of gas is generated inside the battery pack due to a short circuit or the like of the battery, a sheet-like member is broken to release the internal pressure.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the case of a structure that breaks a sheet-like member, there is a concern that oxygen and moisture may flow in from the outside after the breakage, leading to the generation of flammable gases such as hydrogen sulfide in all the individual batteries. An object of the present invention is to relieve an increase in internal pressure and prevent the inflow of air and water in a vehicle battery pack.

Means for Solving the Problems

[0005] According to one aspect of the present invention, a vehicle battery pack includes a housing and a deployment portion. The housing houses a battery containing a solid electrolyte. The deployment portion is connected to a connection port of the housing and expands to form a closed space when the internal pressure of the housing rises.

Effects of the Invention

[0006] According to the present invention, it is possible to relieve the pressure increase inside the housing by the deployment of the deployment portion. Further, since the deployed deployment portion is a closed space, it is possible to prevent the inflow of air and water.

Brief Description of the Drawings

[0007] [Figure 1] This is a diagram showing a vehicle battery pack according to the first embodiment. [Figure 2] This diagram shows the internal pressure of the enclosure during a short circuit. [Figure 3] This is a diagram showing the arrangement of the unfolding section. [Figure 4] This diagram shows the arrangement of the connection ports for the battery. [Figure 5] This figure shows a vehicle battery pack according to the second embodiment. [Figure 6] This figure shows a vehicle battery pack according to the third embodiment. [Figure 7] This figure shows a vehicle battery pack according to the fourth embodiment. [Figure 8] This is a diagram showing the deployment sensor and controller. [Figure 9] This indicates a deployable sensor. [Modes for carrying out the invention]

[0008] Embodiments of the present invention will be described below with reference to the drawings. Note that the drawings are schematic and may differ from actual examples. Furthermore, the following embodiments are illustrative examples of devices and methods for realizing the technical concept of the present invention, and do not limit the configuration to those described below. In other words, the technical concept of the present invention can be modified in various ways within the technical scope described in the claims.

[0009] 《First Embodiment》 "composition" Figure 1 shows a vehicle battery pack 11 according to the first embodiment. The vehicle battery pack 11 is installed in electric vehicles and hybrid vehicles as a power source for vehicle propulsion, and comprises a housing 12 and a deployment section 13. The housing 12 is made of a metal such as aluminum and houses a battery 15 consisting of multiple stacked modules. The battery 15 is an all-solid-state battery, but it is acceptable as long as it contains at least a portion of a solid electrolyte. Since sulfide-based solid electrolytes react with moisture to generate flammable gases such as hydrogen sulfide, it is necessary to prevent air and water from entering the housing 12. The internal pressure of the housing 12 increases when the battery 15 overheats due to a short circuit.

[0010] The unfolding section 13 is connected to the connection port 21 of the housing 12 and functions as a chamber that unfolds to form a closed space when the internal pressure of the housing 12 rises. Figure (a) shows the state before unfolding, and Figure (b) shows the state after unfolding. The connection port 21 is formed on the bottom surface of the housing 12. The unfolding section 13 is normally folded and is a bag-like member that expands and unfolds when the internal pressure of the housing 12 rises due to the heat generated by the battery 15. The bag-like member is made of a synthetic resin with excellent heat resistance, such as polyester, but aramid paper or fiber paper may also be used as long as it can unfold in accordance with the internal pressure of the housing 12.

[0011] Figure 2 shows the internal pressure of the housing 12 during a short circuit. Here, the horizontal axis represents time, and the vertical axis represents the internal pressure of the housing 12. When the battery 15 generates heat due to a short circuit, the internal pressure of the housing 12 temporarily increases due to the expansion of air. The reason why the increase in internal pressure is temporary is that all-solid-state batteries do not contain electrolyte, and even if a short circuit occurs, the increase in pressure due to gas generation is small. Therefore, since the increase in internal pressure during a short circuit quickly decreases, the volume of the unfolding section 13 should be set to an amount that can absorb the temporary increase in internal pressure. Figure 3 shows the arrangement of the unfolding section 13. This shows the deployed section 13 after it has been unfolded. The vehicle battery pack 11 is located under the floor of the vehicle body 23, and the deployed section 13 unfolds below the vehicle body 23, that is, between the vehicle body 23 and the road surface.

[0012] Figure 4 shows the arrangement of the connection ports 21 for the battery 15. Here, a cross-section of the housing 12 as viewed from the side is shown. The connection port 21 is formed on a wall that is not adjacent to the battery 15. For example, as shown in (a) in the figure, when auxiliary components 26 are housed in the housing 12, the connection port 21 is disposed below the auxiliary components 26. The auxiliary components 26 are a cooling fan, a junction box, and the like. As shown in (b) in the figure, when there is a partition wall 27 that constitutes a housing section for the battery 15 in the housing 12, the connection port 21 is disposed on a wall outside the partition wall 27 with respect to the battery 15. The partition wall 27 is a partition wall that rises from the floor surface inside the housing 12 and does not block up to the ceiling. Here, in order to shorten the distance from the battery 15, the connection port 21 is formed on the side surface of the housing 12, but it may be formed on the bottom surface of the housing 12.

[0013] [[Effect]] Next, the main effects of the first embodiment will be described. (1) The vehicle battery pack 11 includes a housing 12 and a deployment section 13. The housing 12 houses a battery 15 containing a solid electrolyte. The deployment section 13 is connected to the connection port 21 of the housing 12 and expands to form a closed space when the internal pressure of the housing 12 rises. Thereby, the pressure increase inside the housing 12 can be alleviated by the expansion of the deployment section 13. Further, since the deployed deployment section 13 is a closed space, the inflow of air and water can be prevented. (2) The deployment section 13 expands below the vehicle body. Thereby, the distance between the battery 15 and the deployment section 13 becomes shorter, and air quickly flows into the deployment section 13.

[0014] (3) The connection port 21 is formed on the bottom surface of the housing 12. Thereby, the distance between the battery 15 and the deployment section 13 becomes shorter, and air quickly flows into the deployment section 13. (4) The connection port 21 is formed on a wall that is not adjacent to the battery 15. Thereby, it is possible to prevent the heated air from flowing directly into the deployment section 13 and protect the deployment section 13 from heat. (5) The deployment section 13 is a bag member that is normally folded and expands and deploys when the internal pressure of the housing 12 rises due to the heat generation of the battery 15. Thereby, the deployment section 13 can be easily configured.

[0015] Second Embodiment Configuration The second embodiment has the same configuration as the first embodiment described above, except that a new configuration is added. Therefore, the same reference numerals are assigned to the common parts, and detailed description thereof is omitted. FIG. 5 is a diagram showing the vehicle battery pack 11 of the second embodiment. A connection path 31 leading to the connection port 21 is formed in the housing 12. The vehicle battery pack 11 includes a cooling unit 32. The cooling unit 32 is a cooling pipe branched from an existing cooling system mounted on the vehicle, through which a refrigerant or cooling water flows. The cooling unit 32 cools the air in the connection path 31 by heat exchange with the refrigerant or cooling water. Cooling fins may be provided instead of the cooling pipe.

[0016] Operational Effects Next, the main operational effects of the second embodiment will be described. (1) A connection path 31 leading to the connection port 21 is formed in the housing 12. The vehicle battery pack 11 includes a cooling unit 32. The cooling unit 32 cools the connection path 31. Thereby, the air flowing into the deployment part 13 can be cooled, and the deployment part 13 can be protected from heat. Other operational effects brought about by the common configuration are the same as those of the first embodiment described above.

[0017] Third Embodiment Configuration The third embodiment has the same configuration as the first embodiment described above, except that a new configuration is added. Therefore, the same reference numerals are assigned to the common parts, and detailed description thereof is omitted. FIG. 6 is a diagram showing the vehicle battery pack 11 of the third embodiment. The vehicle battery pack 11 includes a restraint member 35. The restraint member 35 is, for example, an adhesive tape or a fastener, etc. and normally restrains the deployment part 13 to the housing 12 and breaks to release the restraint when the deployment part 13 is deployed. It is preferable to form a breakable part such as a cut, a thin part, a concave groove, etc. in the restraint member 35.

[0018] Effects and Benefits Next, the main effects and advantages of the third embodiment will be described. (1) The vehicle battery pack 11 is equipped with a restraining member 35. The restraining member 35 normally restrains the deployment section 13 to the housing 12 and releases the restraint when the deployment section 13 is deployed. This prevents the deployment section 13 from unintentionally deploying and air from flowing in when the battery 15 becomes hot within the normal operating range that is not a short circuit. Other effects and benefits resulting from the common configuration are the same as those of the first embodiment described above.

[0019] 《Fourth Embodiment》 "composition" The fourth embodiment has the same configuration as the first embodiment described above, except for the addition of a new configuration. Therefore, common parts are denoted by the same reference numerals, and a detailed explanation is omitted. Figure 7 shows a vehicle battery pack 11 according to the fourth embodiment. The vehicle battery pack 11 includes a sheet member 37. The sheet member 37 is, for example, a metal foil or a thin sheet of synthetic resin, and it closes the connection port 21 and breaks when the internal pressure of the housing 12 increases.

[0020] Effects and Benefits Next, the main effects and advantages of the fourth embodiment will be described. (1) The vehicle battery pack 11 is equipped with a sheet member 37. The sheet member 37 closes the connection port 21 and ruptures when the internal pressure of the housing 12 rises. This prevents the unintended deployment section 13 from deploying and air from flowing in when the battery 15 becomes hot within the normal operating range that is not a short circuit. Other effects and benefits resulting from the common configuration are the same as those of the first embodiment described above.

[0021] 《Fifth Embodiment》 "composition" The fifth embodiment has the same configuration as the first embodiment described above, except for the addition of a new configuration. Therefore, common parts are denoted by the same reference numerals, and a detailed explanation is omitted. Figure 8 shows the deployment sensor 41 and the controller 42. The vehicle battery pack 11 includes a deployment sensor 41 (detection unit) and a controller 42. The deployment sensor 41 detects whether or not the deployment unit 13 has been deployed. The controller 42 is composed of, for example, a microcomputer and executes a process to determine if there is an abnormality in the battery 15 according to the detection result of the deployment sensor 41. When the controller 42 detects an abnormality in the battery 15, it illuminates, for example, a warning light.

[0022] Figure 9 shows the deployment sensor 41. Figure (a) uses wiring 45 as the deployment sensor 41. Wiring 45 is provided to hold down the deployment section 13 before deployment and is configured to break when the deployment section 13 is deployed. Controller 42 detects the resistance value of wiring 45 and determines that the deployment section 13 is not deployed if there is continuity, and determines that the deployment section 13 has been deployed if there is no continuity in wiring 45. Figure (b) uses strain gauge 46 as the deployment sensor 41. Strain gauge 46 is provided on the deployment side of the deployment section 13 and is configured to be pressed when the deployment section 13 is deployed. Controller 42 detects the voltage signal of strain gauge 46 and determines that the deployment section 13 is not deployed if it is not pressed, and determines that the deployment section 13 has been deployed if it is pressed. Figure (c) uses laser sensor 47 as the deployment sensor 41. The laser sensor 47 is positioned so that its optical axis crosses the deployment side of the deployment section 13, and is configured to block the signal light when the deployment section 13 is deployed. The controller 42 detects the electrical signal from the laser sensor 47 and determines that the deployment section 13 is not deployed if the signal light is not blocked, and determines that the deployment section 13 has been deployed if the signal light is blocked.

[0023] Effects and Benefits Next, the main effects and advantages of the fifth embodiment will be described. (1) The vehicle battery pack 11 includes a deployment sensor 41 and a controller 42. The deployment sensor 41 detects whether or not the deployment unit 13 has been deployed. The controller 42 performs a process to determine if there is an abnormality in the battery 15 according to the detection result of the deployment sensor 41. This makes it possible to accurately determine if there is an abnormality in the battery 15 in conjunction with the deployment of the deployment unit 13. Other effects and benefits resulting from the common configuration are the same as those of the first embodiment described above.

[0024] Although the above description has been made with reference to a limited number of embodiments, the scope of the rights is not limited to these, and modifications of the embodiments based on the above disclosure will be obvious to those skilled in the art. Furthermore, each embodiment and modification can be adopted in any combination. [Explanation of symbols]

[0025] 11... Vehicle battery pack, 12... Housing, 13... Deployment section, 15... Battery, 21... Connection port, 23... Vehicle body, 26... Auxiliary parts, 27... Bulkhead, 31... Connection path, 32... Cooling section, 35... Restraining member, 37... Seat member, 41... Deployment sensor, 42... Controller, 45... Wiring, 46... Strain gauge, 47... Laser sensor

Claims

1. A housing containing a battery with a solid electrolyte, A vehicle battery pack characterized by comprising: a deployment section connected to the connection port of the housing, which deploys to form a closed space when the internal pressure of the housing rises.

2. The vehicle battery pack according to claim 1, characterized in that the unfolding section unfolds downwards on the vehicle body.

3. The vehicle battery pack according to claim 2, characterized in that the connection port is formed on the bottom surface of the housing.

4. The vehicle battery pack according to claim 1, characterized in that the connection port is formed in a wall that is not adjacent to the battery.

5. The housing has a connection path formed therein leading to the connection port. The vehicle battery pack according to claim 1, characterized in that it is provided with a cooling unit for cooling the aforementioned connection path.

6. The vehicle battery pack according to claim 1, characterized in that it includes a restraining member that restrains the unfolding portion to the housing under normal conditions and releases the restraint when the unfolding portion is unfolded.

7. The vehicle battery pack according to claim 1, further comprising a sheet member that closes the connection port and breaks when the internal pressure of the housing rises.

8. A detection unit for detecting whether or not the unfolding unit has been unfolded, The vehicle battery pack according to claim 1, further comprising a controller that performs a process to determine if the battery is abnormal according to the detection result of the detection unit.

9. The vehicle battery pack according to claim 1, characterized in that the unfolding portion is a bag-like member that is normally folded and expands and unfolds when the internal pressure of the housing rises due to the heat generated by the battery.

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