battery cell

Abstract

We propose a technology to suppress the rise in internal pressure of the containment member. [Solution] The battery cell comprises a battery body, an internal device, and a housing member that contains the battery body, the internal device, and the electrolyte. The internal device comprises a container, a thermal expansion member housed within the container that expands in accordance with the temperature of the battery cell, and a needle housed within the container that protrudes from the container and penetrates the housing member due to the thermal expansion of the thermal expansion member.

Description

Technical Field

[0001] The technology disclosed in the present specification relates to a battery cell.

Background Art

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

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] An electrolytic solution is housed in the housing member. The battery main body is immersed in the electrolytic solution inside the housing member. When the temperature of the battery cell rises during charging and discharging of the battery cell, gas is generated from the electrolytic solution. The generated gas raises the internal pressure of the housing member. The present specification proposes a technique for suppressing an increase in the internal pressure of the housing member.

Means for Solving the Problems

[0005] The battery cell disclosed in the present specification includes a battery main body, an internal device, and a housing member that houses the battery main body, the internal device, and an electrolytic solution. The internal device includes a container, a thermal expansion member that is housed in the container and thermally expands in accordance with the temperature of the battery cell, and a needle that is housed in the container and protrudes from the container to penetrate the housing member by thermal expansion of the thermal expansion member.

[0006] According to the battery cell described above, when the temperature of the battery cell rises, the needle penetrates the housing member. As a result, the gas generated by the temperature rise of the battery cell is discharged to the outside of the housing member through the through-hole formed in the housing member. This suppresses the rise in internal pressure of the housing member. [Brief explanation of the drawing]

[0007] [Figure 1] This is a perspective view of the battery cell in the embodiment. [Figure 2] This is a top view of the battery cell in the embodiment. [Figure 3] This is a top view of the battery cell before the housing component is sealed. [Figure 4] This is a schematic diagram of the internal components. [Modes for carrying out the invention]

[0008] The battery cells disclosed herein may have electrode plates. The electrode plates may be connected to the battery body and may extend from the side of the battery body to the outside of the housing member. The internal components may be positioned adjacent to the electrode plates in the width direction and adjacent to the side.

[0009] According to the above embodiment, the storage member is less likely to wrinkle. [Examples]

[0010] The battery cell 100 shown in Figure 1 is, for example, mounted in an electric vehicle. The battery cell 100 has a roughly rectangular plate shape. Hereafter, the thickness direction of the battery cell 100 will be referred to as the z direction, the longitudinal direction of the battery cell 100 will be referred to as the x direction, and the width direction of the battery cell 100 (i.e., the direction perpendicular to the z and x directions) will be referred to as the y direction. When the battery cell 100 is in use, multiple battery cells 100 are stacked in the z direction to form a battery module. As shown in Figure 1, the battery cell 100 has a housing member 20. As shown in Figure 2, the battery body 10 and internal device 60 are housed inside the housing member 20. The housing member 20 houses the battery body 10, the internal device 60, and the electrolyte. 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. The electrode plates 50 and 52 are connected to the battery body 10.

[0011] The battery body 10 is a battery that can be repeatedly charged and discharged. As shown in Figure 2, the battery body 10 has a roughly plate-like shape. The battery body 10 is a laminate in which multiple positive electrode current collector foils and negative electrode current collector foils are arranged alternately in the z direction via a separator. Although not shown, one end of the battery body 10 in the x direction is provided with a positive electrode foil section, which is made up of bundled positive electrode current collector foils. An electrode plate 50 is connected to the positive electrode foil section. Also, although not shown, the other end of the battery body 10 in the x direction is provided with a negative electrode foil section, which is made up of bundled negative electrode current collector foils. An electrode plate 52 is connected to the negative electrode foil section. The battery body 10 is immersed in an electrolyte solution filled inside the housing member 20.

[0012] Figure 3 is a cross-sectional view of the battery cell 100 before sealing the housing member 20. As shown in Figure 3, the housing member 20 is made of a film. As the film constituting the housing member 20, for example, a laminate film can be used in which a resin coating layer is provided on both surfaces of an aluminum film. The film constituting the housing member 20 is formed into a container shape having a first film portion 22 and a second film portion 32 by embossing. A fold 21 is provided on the side surface of the housing member 20. The second film portion 32 can pivot relative to the first film portion 22 around the fold 21.

[0013] The first film portion 22 has a housing portion 24 and a frame portion 26. The housing portion 24 has a cup shape with a recess capable of housing the battery body 10. The lower part of the battery body 10 is housed in the housing portion 24. The frame portion 26 is provided around the housing portion 24. The second film portion 32 has a housing portion 34 and a frame portion 36. The housing portion 34 has a cup shape with a recess capable of housing the battery body 10. The frame portion 36 is provided around the housing portion 34. When the housing member 20 is closed, the housing portion 34 covers the upper surface 10a of the battery body 10. Also, when the housing member 20 is closed, the frame portion 36 overlaps the frame portion 26. In the portion where the frame portion 36 and the frame portion 26 overlap, the lower surface of the frame portion 36 (i.e., the surface that becomes the inside of the housing member 20) and the upper surface of the frame portion 26 (i.e., the surface that becomes the inside of the housing member 20) are welded together. Hereinafter, the portion where frame portion 36 and frame portion 26 overlap will be referred to as the welded portion 40. As shown in Figures 1 and 2, the housing member 20 has sides 20a to 20d. Sides 20a and 20c are sides that extend in the short direction of the housing member 20. Sides 20b and 20d are sides that extend in the longitudinal direction of the housing member 20. The aforementioned fold 21 is provided on side 20d. The welded portion 40 is provided on sides 20a to 20c. The welded portion 40 protrudes from sides 20a to 20c. The housing member 20 is sealed at the welded portion 40.

[0014] As shown in Figures 1 and 2, the electrode plate 50 extends from the side surface 10b of the battery body 10 to the outside of the housing member 20. The electrode plate 50 extends from the inside to the outside of the housing member 20 through the interface between the frame portion 26 and the frame portion 36. The electrode plate 52 extends from the side surface 10c of the battery body 10 to the outside of the housing member 20. The electrode plate 52 extends from the inside to the outside of the housing member 20 through the interface between the frame portion 26 and the frame portion 36. In the area of ​​the welded portion 40 where the electrode plates 50 and 52 are not present, the frame portion 36 is welded to the frame portion 26. In the area of ​​the welded portion 40 where the electrode plate 50 is present, the frame portion 26 is welded to the lower surface of the electrode plate 50, and the frame portion 36 is welded to the upper surface of the electrode plate 50. In the region of the welded area 40 where the electrode plate 52 is present, the frame portion 26 is welded to the lower surface of the electrode plate 52, and the frame portion 36 is welded to the upper surface of the electrode plate 52.

[0015] As shown in Figures 1 and 2, the battery cell 100 has an internal device 60. The internal device 60 is housed within the housing member 20. The internal device 60 is positioned adjacent to the electrode plate 52 in the y-direction. The internal device 60 is also positioned adjacent to the side surface 10c of the battery body 10. The internal device 60 is located at the corner between the side surfaces 20b and 20c of the housing member 20. The upper surface 60a of the internal device 60 faces the film that constitutes the upper surface 20e of the housing member 20.

[0016] As shown in Figure 4, 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 top surface 60a) is in contact with the film that constitutes the top surface 20e of the housing 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 in the top surface 60a of the container 62. The support plate 63 is arranged parallel to the top surface 60a. The needle 64 is fixed to the top surface of the support plate 63. The needle 64 extends upward from the support plate 63. The needle 64 is located 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. When the thermal expansion member 66 expands, the support plate 63 moves upward together with the needle 64.

[0017] During charging and discharging of the battery cell 100, heat is generated in the battery body 10, causing the temperature of the battery cell 100 to rise. When the temperature of the battery cell 100 rises, gas is generated from the electrolyte, which may cause the internal pressure of the housing member 20 to rise. In this embodiment, when the temperature of the battery cell 100 rises, the thermal expansion member 66 in the internal device 60 expands due to thermal expansion, and the needle 64 moves upward inside the container 62. When 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, and the needle 64 penetrates the housing member 20 (i.e., the film). Gas inside the housing member 20 is discharged to the outside of the housing member 20 through the through hole formed by the needle 64. This prevents an excessive rise in the internal pressure of the housing member 20.

[0018] Furthermore, in the above-described embodiment, the internal device 60 is positioned at the corner between the side 20b and the side 20c. Therefore, wrinkles are less likely to occur in the film at the corner.

[0019] In the embodiment described above, the internal device 60 was positioned adjacent to the electrode plate 52 in the y-direction and adjacent to the side surface 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 surface 10b of the battery body 10.

[0020] In the above-described embodiment, the internal device 60 forms a through-hole in the film constituting the upper surface 20e of the housing member 20 when the temperature rises, but the through-hole may be formed in another portion of the film constituting the housing member 20.

[0021] Although the embodiments have been described in detail above, these are merely illustrative and do not limit the scope of the claims. The technology described in the claims includes various modifications and alterations of the specific examples illustrated above. The technical elements described in the present specification or drawings exhibit technical utility alone or in various combinations, and are not limited to the combinations described in the claims as filed. In addition, the technologies illustrated in the present specification or drawings achieve a plurality of purposes at the same time, and achieving one of the purposes itself has technical utility.

Description of Reference Signs

[0022] 10 : Battery main body 10b : Side surface 10c : Side surface 20 : Housing member 50 : Electrode plate 52 : Electrode plate 60 : Internal device 62 : Container 64 : Needle 66 : Thermal expansion member 100 : Battery cell

Claims

1. It is a battery cell, The battery unit and Internal device and, The battery body, the internal device, and the storage member containing the electrolyte, It has, The aforementioned internal device Container and A thermal expansion member housed within the aforementioned container expands in temperature according to the temperature of the battery cell, A needle is housed within the container and protrudes from the container and penetrates the housing member due to the thermal expansion of the thermal expansion member. Having, Battery cell.

2. It further comprises electrode plates connected to the battery body and extending from the side of the battery body to the outside of the housing member, The internal device is positioned adjacent to the electrode plate in the width direction and adjacent to the side surface. The battery cell according to claim 1.

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