Battery cell

Abstract

Provided is a technique for suppressing an increase in internal pressure of a housing member. A battery cell includes a battery main body, an internal device, and a housing member that houses the battery main body, the internal device, and an electrolyte. The internal device includes a container, a thermal expansion member housed in the container and thermally expanded in accordance with a temperature of the battery cell, and a needle housed in the container and protruding from the container by thermal expansion of the thermal expansion member and penetrating the housing member.

Description

Technical Field

[0001] The technology disclosed in this specification relates to a battery cell. Background Technology

[0002] The battery cell in Patent Document 1 has a battery body and a housing component. The battery body is housed in the housing component.

[0003] Patent Document 1: Japanese Patent Application Publication No. 2020-004712 Summary of the Invention

[0004] An electrolyte is contained within a housing. The battery body is immersed in the electrolyte inside the housing. If the temperature of the battery cell rises during charging and discharging, gas is generated from the electrolyte. The generated gas causes the internal pressure of the housing to increase. This specification proposes a technique to suppress the increase in internal pressure of the housing.

[0005] The battery cell disclosed in this specification includes: a battery body; an internal device; and a housing component that houses the battery body, the internal device, and an electrolyte. The internal device includes: a container; a thermal expansion component that is housed within the container and thermally expands according to the temperature of the battery cell; and a needle that is housed within the container, protrudes from the container by the thermal expansion of the thermal expansion component, and penetrates the housing component.

[0006] According to the aforementioned battery cell, if the temperature of the battery cell rises, the needle will penetrate the housing component. Therefore, the gas generated by the temperature rise of the battery cell will be discharged to the outside of the housing component through the through-hole formed in the housing component. As a result, the rise in internal pressure of the housing component can be suppressed. Attached Figure Description

[0007] Figure 1 This is a perspective view of the battery cell in an embodiment.

[0008] Figure 2 This is a top view of the battery cell in the embodiment.

[0009] Figure 3 This is a top view of the battery cell before the components are sealed.

[0010] Figure 4 It is a schematic diagram of the internal components. Detailed Implementation

[0011] The battery cell disclosed in this specification may have an electrode plate. The electrode plate may be connected to the battery body and extend from the side of the battery body to the outside of the receiving member. The internal device may be configured adjacent to the electrode plate in the width direction and adjacent to the side.

[0012] Using the above method, the housing components are less prone to wrinkling.

[0013] Example

[0014] Figure 1 The battery cell 100 shown is, for example, mounted in an electric vehicle. The battery cell 100 has a generally rectangular plate shape. Hereinafter, the thickness direction of the battery cell 100 will be referred to as the z-direction, the length direction of the battery cell 100 as the x-direction, and the width direction of the battery cell 100 (i.e., the direction orthogonal to the z-direction and x-direction) as the y-direction. When using the battery cell 100, multiple battery cells 100 are stacked in the z-direction to form a battery module. Figure 1 As shown, the battery cell 100 has a housing component 20. (As indicated...) Figure 2 As shown, the battery body 10 and the internal device 60 are housed inside the housing component 20. The housing component 20 houses the battery body 10, the internal device 60, and the electrolyte. Furthermore, an electrode plate 50 is provided at one end of the battery cell 100 in the x-direction, and an electrode plate 52 is provided at the other end of the battery cell 100 in the x-direction. Electrode plate 50 is the positive electrode, and electrode plate 52 is the negative electrode. Electrode plates 50 and 52 are connected to the battery body 10.

[0015] The battery body 10 is a battery capable of repeated charging and discharging. For example... Figure 2 As shown, the battery body 10 has a generally plate-like shape. The battery body 10 is a laminated body in which multiple positive and negative current-collecting foils are alternately arranged in the z-direction, separated by a separator. Although not shown, a positive current-collecting foil portion formed by bundling the positive current-collecting foils is provided at one end of the battery body 10 in the x-direction. An electrode plate 50 is connected to the positive current-collecting foil portion. Furthermore, although not shown, a negative current-collecting foil portion formed by bundling negative current-collecting foils is provided at the other end of the battery body 10 in the x-direction. An electrode plate 52 is connected to the negative current-collecting foil portion. The battery body 10 is immersed in an electrolyte filled inside the housing member 20.

[0016] Figure 3 This is a cross-sectional view of the battery cell 100 prior to the sealing housing component 20. (See image.) Figure 3 As shown, the receiving component 20 is made of a film. For example, a laminated film with resin coatings on both surfaces of an aluminum film can be used as the film constituting the receiving component 20. The film constituting the receiving component 20 is embossed into a container shape having a first film portion 22 and a second film portion 32. A crease 21 is provided on the side of the receiving component 20. The second film portion 32 is oscillating relative to the first film portion 22 about the crease 21.

[0017] The first membrane portion 22 has a receiving portion 24 and a frame portion 26. The receiving portion 24 has a cup shape with a recess capable of accommodating the battery body 10. The lower part of the battery body 10 is housed within the receiving portion 24. The frame portion 26 is disposed around the receiving portion 24. The second membrane portion 32 has a receiving portion 34 and a frame portion 36. The receiving portion 34 has a cup shape with a recess capable of accommodating the battery body 10. The frame portion 36 is disposed around the receiving portion 34. When the receiving member 20 is closed, the upper surface 10a of the battery body 10 is covered by the receiving portion 34. Furthermore, when the receiving member 20 is closed, the frame portion 36 overlaps with the frame portion 26. In the overlapping portion of the frame portion 36 and the frame portion 26, the lower surface of the frame portion 36 (i.e., the surface that becomes the inner side of the receiving member 20) and the upper surface of the frame portion 26 (i.e., the surface that becomes the inner side of the receiving member 20) are fused together. Hereinafter, the overlapping portion of the frame portion 36 and the frame portion 26 will be referred to as the welded portion 40. Figure 1 , 2 As shown, the receiving member 20 has sides 20a to 20d. Sides 20a and 20c extend along the short side of the receiving member 20. Sides 20b and 20d extend along the length of the receiving member 20. The aforementioned crease 21 is provided on side 20d. A welded portion 40 is provided on sides 20a to 20c. The welded portion 40 protrudes from sides 20a to 20c. The receiving member 20 is sealed in the welded portion 40.

[0018] like Figure 1 , 2 As shown, electrode plate 50 extends from side 10b of battery body 10 to the outer side of receiving member 20. Electrode plate 50 extends from the inside to the outside of receiving member 20 through the interface between frame portion 26 and frame portion 36. Electrode plate 52 extends from side 10c of battery body 10 to the outside of receiving member 20. Electrode plate 52 extends from the inside to the outside of receiving member 20 through the interface between frame portion 26 and frame portion 36. In the area of ​​welding portion 40 where electrode plates 50 and 52 are not present, frame portion 36 is welded to frame portion 26. In the area of ​​welding portion 40 where electrode plate 50 is present, frame portion 26 is welded to the lower surface of electrode plate 50, and frame portion 36 is welded to the upper surface of electrode plate 50. In the area of ​​welding portion 40 where electrode plate 52 is present, frame portion 26 is welded to the lower surface of electrode plate 52, and frame portion 36 is welded to the upper surface of electrode plate 52.

[0019] like Figure 1 , 2As shown, the battery cell 100 has an internal device 60. The internal device 60 is housed within the receiving member 20. The internal device 60 is positioned adjacent to the electrode plate 52 in the y-direction. Furthermore, the internal device 60 is positioned adjacent to the side surface 10c of the battery body 10. The internal device 60 is positioned at the corner between the side surface 20b and the side surface 20c of the receiving member 20. The upper surface 60a of the internal device 60 faces the membrane constituting the upper surface 20e of the receiving member 20.

[0020] like Figure 4 As shown, the internal device 60 includes a container 62, a support plate 63, a needle 64, and a thermal expansion member 66. The surface of the container 62 (i.e., the upper surface 60a) is in contact with the membrane constituting the upper surface 20e of the receiving member 20. The support plate 63, the needle 64, and the thermal expansion member 66 are housed inside the container 62. The container 62 has, for example, a cylindrical shape. A through hole 62a is provided on the upper surface 60a of the container 62. The support plate 63 is arranged parallel to the upper surface 60a. The needle 64 is fixed to the upper surface of the support plate 63. The needle 64 rises upward from the support plate 63. The needle 64 is positioned below the through hole 62a. The thermal expansion member 66 is positioned between the support plate 63 and the bottom surface of the container 62. If the thermal expansion member 66 thermally expands, the support plate 63 and the needle 64 move upward together.

[0021] During the charging and discharging process of the battery cell 100, the battery body 10 generates heat, and the temperature of the battery cell 100 rises. If the temperature of the battery cell 100 rises, gas may be generated from the electrolyte, and the internal pressure of the housing 20 may increase. In this embodiment, if the temperature of the battery cell 100 rises, the thermal expansion member 66 in the internal device 60 thermally expands, and the needle 64 moves upward within the container 62. If the temperature of the battery cell 100 exceeds a predetermined value, the needle 64 protrudes from the through hole 62a to the outside of the container 62, penetrating the housing 20 (i.e., the membrane). Through the through hole formed by the needle 64, the gas inside the housing 20 is discharged to the outside of the housing 20. Therefore, excessive increase in the internal pressure of the housing 20 can be prevented.

[0022] Furthermore, in the above embodiment, the internal device 60 is disposed at the corner between side 20b and side 20c. Therefore, the membrane at the corner is less prone to wrinkling.

[0023] In the above embodiment, the internal device 60 is positioned adjacent to the electrode plate 52 in the y-direction and adjacent to the side 10c of the battery body 10. However, the internal device 60 may also be positioned adjacent to the electrode plate 50 in the y-direction and adjacent to the side 10b of the battery body 10.

[0024] In the above embodiment, the internal device 60 forms a through hole in the membrane constituting the upper surface 20e of the receiving member 20 when the temperature rises, but through holes may also be formed in other parts of the membrane constituting the receiving member 20.

[0025] The embodiments have been described in detail above, but these are merely illustrative and do not limit the scope of the claims. The technology described in the claims includes various modifications and variations of the specific examples illustrated above. The technical elements described in this specification or drawings achieve technical utility through individual or various combinations, and are not limited to the combinations described in the claims at the time of application. Furthermore, the technology illustrated in this specification or drawings simultaneously achieves multiple objectives, wherein achieving one objective is itself technically practical.

[0026] Symbol Explanation

[0027] 10-Battery body, 10b-Side, 10c-Side, 20-Housing component, 50-Electrode plate, 52-Electrode plate, 60-Internal device, 62-Container, 64-Pin, 66-Thermal expansion component, 100-Battery cell.

Claims

1. A battery cell, characterized in that, have: Battery body; Internal devices; and A housing component that houses the battery body, the internal devices, and the electrolyte. The internal device has: container; A thermal expansion component, which is housed within the container and thermally expands according to the temperature of the battery cell; and The needle, which is contained within the container, protrudes from the container and penetrates the containing member due to thermal expansion of the thermal expansion member.

2. The battery cell according to claim 1, characterized in that, It also has: An electrode plate, which is connected to the battery body and extends from the side of the battery body to the outside of the receiving component, The internal device is positioned adjacent to the electrode plate in the width direction and adjacent to the side surface.

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