storage battery cell

Abstract

The present application aims to stably electrically connect an electrode body and an external terminal and increase the volume ratio of the electrode body in a power storage battery cell. The power storage battery cell includes an electrode body, an external terminal, and a current collecting member. The current collecting member is formed of an integral member. The current collecting member includes a shaft portion, a first locking portion, and a second locking portion. The first locking portion or the second locking portion is formed by riveting. The shaft portion penetrates the electrode body and the external terminal in the axial direction. The first locking portion is connected to one end of the shaft portion in the axial direction and is locked to the electrode body. The second locking portion is connected to the other end of the shaft portion in the axial direction and is locked to the external terminal. The contact area of the first locking portion with the electrode body is larger than the cross-sectional area of the shaft portion in a direction perpendicular to the axial direction. The contact area of the second locking portion with the external terminal is larger than the cross-sectional area.

Description

Technical Field

[0001] This invention relates to a battery cell. Background Technology

[0002] Patent Document 1 (Japanese Patent Application Publication No. 2022-042676) discloses a secondary battery. The secondary battery includes an external terminal and a current collector terminal. The current collector terminal has a riveting portion. One axial end of the riveting portion is electrically connected to an electrode body. One end of the current collector terminal is connected to the electrode body via a connecting member. The other axial end of the riveting portion is riveted to the external terminal. The riveting portion is welded or brazed to the external terminal.

[0003] Patent Document 1: Japanese Patent Application Publication No. 2022-042676 Summary of the Invention

[0004] By configuring a connecting component between the current collector (current collector terminal) and the electrode body, the electrode body and the external terminal are stably electrically connected to each other. However, due to the presence of the connecting component, the volume ratio of the electrode body in the energy storage cell (secondary battery) is limited, thereby limiting the energy density of the energy storage cell.

[0005] The present invention was made in view of the above-mentioned problems, and its object is to provide a battery cell that can stably connect the electrode body to the external terminal and can improve the volume ratio of the electrode body in the battery cell.

[0006] According to one aspect of the present invention, a battery cell includes an electrode body, external terminals, and a current collector. The current collector is constructed as a single unit. The current collector includes a shaft portion, a first locking portion, and a second locking portion. The first locking portion or the second locking portion is formed by riveting. The shaft portion extends axially through the electrode body and the external terminals. The first locking portion is connected to one axial end of the shaft portion and locks against the electrode body. The second locking portion is connected to the other axial end of the shaft portion and locks against the external terminals. The contact area between the first locking portion and the electrode body is larger than the cross-sectional area of ​​the shaft portion in a direction perpendicular to the axial direction. The contact area between the second locking portion and the external terminals is larger than the aforementioned cross-sectional area.

[0007] Invention Effects

[0008] According to the present invention, it is possible to stably connect the electrode body to the external terminal and to increase the volume ratio of the electrode body in the battery cell. Attached Figure Description

[0009] Figure 1 This is a cross-sectional view showing a battery cell according to an embodiment of the present invention.

[0010] Figure 2 This is a diagram showing a portion of the battery cell viewed from the direction of the arrow shown in II.

[0011] Figure 3 This is a diagram showing a portion of the battery cell viewed from the direction of arrow III. Detailed Implementation

[0012] Hereinafter, a battery cell according to an embodiment of the present invention will be described with reference to the accompanying drawings. Identical or corresponding parts in the drawings will be labeled with the same symbols, and their descriptions will not be repeated.

[0013] Figure 1 This is a cross-sectional view showing a battery cell according to an embodiment of the present invention. Figure 1 The battery cell 1 shown can be installed in electric vehicles such as plug-in hybrid electric vehicles (PHEVs) or battery electric vehicles (BEVs). The battery cell 1 can supply electricity to drive the vehicle. Examples of battery cells 1 include secondary batteries such as lithium-ion batteries, nickel-metal hydride batteries, or sodium-ion batteries. The secondary battery type can be a liquid-cooled secondary battery or a solid-state secondary battery.

[0014] like Figure 1 As shown, the battery cell 1 according to one embodiment of the present invention includes an electrode body 10, an external terminal 20, a current collector 30, and an outer casing 40.

[0015] The electrode body 10 includes a stacked electrode section 11 and a plurality of electrode foils 12. The stacked electrode section 11 is formed by stacking first electrodes 11a and second electrodes 11b together in a direction orthogonal to the axial direction, separated by a separator 11c. The axial direction is indicated by the symbol "D" in the drawings. One of the first electrodes 11a and the second electrodes 11b is a positive electrode and the other is a negative electrode. The stacked electrode section 11 can be formed by alternately stacking a plurality of first electrodes 11a and a plurality of second electrodes 11b. The stacked electrode section 11 can also be formed by winding a first electrode 11a and a second electrode 11b that are stacked together. A solid electrolyte can also be provided instead of the separator 11c. The stacked electrode section 11 is arranged side by side with the current collector 30 in the axial direction.

[0016] Multiple electrode foils 12 extend from the portion of the first electrode 11a that does not face the current collector 30. The multiple electrode foils 12 can extend from a single first electrode 11a or from each of the multiple first electrodes 11a. Furthermore, in this embodiment, the multiple electrode foils 12 are not soldered to each other. The thickness of each of the multiple electrode foils 12 is, for example, greater than 1 μm and less than 100 μm. The multiple electrode foils 12 are made of a metal such as aluminum or a frame.

[0017] The external terminal 20 is configured to be exposed on the outside of the battery cell 1. The external terminal 20 is made of metal. The external terminal 20 is in axial contact with one of the plurality of electrode foils 12.

[0018] Figure 2 This is a diagram showing a portion of the battery cell viewed from the direction of the arrow shown in II. Figure 3 This is a diagram showing a portion of the battery cell viewed from the direction of arrow III.

[0019] like Figures 1 to 3 As shown, the current collector 30 is a single, integral component. The current collector 30 is made of metal. The current collector 30 is electrically connected to both the electrode body 10 and the external terminal 20 through contact. However, the current collector 30 is not soldered to either the electrode body 10 or the external terminal 20.

[0020] The current collector 30 includes a shaft portion 31, a first locking portion 32, and a second locking portion 33. The shaft portion 31 has a cylindrical shape with a central axis along the axial direction. Figures 1 to 3 In the diagram, the central axis is represented by the symbol "C". The shaft portion 31 extends axially through the electrode body 10 and the external terminal 20. Specifically, the shaft portion 31 extends through a plurality of electrode foils 12 that are stacked between the external terminal 20 and the first locking portion 32.

[0021] The first locking portion 32 is connected to one axial end of the shaft portion 31 and locks into the electrode body 10. The contact area between the first locking portion 32 and the electrode body 10 is larger than the cross-sectional area of ​​the shaft portion 31 along the direction perpendicular to the axial direction. Figure 2 In this context, the aforementioned contact surface is represented by the symbol "S1". Figure 2 and Figure 3 In the above section, the cross section is represented by the symbol "SA". In the first locking part 32, the entire surface facing the shaft part 31 in the axial direction is in contact with the electrode body 10. Specifically, in the first locking part 32, the entire surface facing the shaft part 31 in the axial direction is in contact with one of the plurality of electrode foils 12.

[0022] The second locking portion 33 is connected to the other end of the shaft portion 31 in the axial direction and locks with the external terminal 20. The contact area between the second locking portion 33 and the external terminal 20 is larger than the aforementioned cross-sectional area. Figure 3 In this context, the aforementioned contact surface is represented by the symbol "S2". In the second locking portion 33, the entire surface facing the shaft portion 31 in the axial direction is in contact with the external terminal 20.

[0023] The first locking portion 32 or the second locking portion 33 is formed by riveting. One of the first locking portions 32 and the second locking portion 33, when viewed axially, has a circular shape centered on the central axis. In this embodiment, the other locking portion of the first locking portion 32 and the second locking portion 33 also has a circular shape centered on the central axis when viewed axially, but the shape of this other locking portion is not particularly limited. When viewed axially, the other locking portion of the first locking portion 32 and the second locking portion 33 may have a rectangular shape. In this embodiment, specifically, the second locking portion 33 is formed by riveting, whereby the material used to form the current collector 30 is flattened.

[0024] The outer casing 40 can be a laminated outer casing or a square metal housing. The outer casing 40 houses the electrode body 10 within its receiving space. A portion of the external terminal 20 is disposed outside the receiving space of the outer casing 40.

[0025] As described above, an embodiment of the present invention relates to a battery cell 1 comprising an electrode body 10, an external terminal 20, and a current collector 30. The current collector 30 is a single, integral component. The current collector 30 includes a shaft portion 31, a first locking portion 32, and a second locking portion 33. The first locking portion 32 or the second locking portion 33 is formed by riveting. The shaft portion 31 extends axially through the electrode body 10 and the external terminal 20. The first locking portion 32 is connected to one axial end of the shaft portion 31 and locks against the electrode body 10. The second locking portion 33 is connected to the other axial end of the shaft portion 31 and locks against the external terminal 20. The contact area between the first locking portion 32 and the electrode body 10 is larger than the cross-sectional area of ​​the shaft portion 31 in a direction perpendicular to the axial direction. The contact area between the second locking portion 33 and the external terminal 20 is larger than the aforementioned cross-sectional area.

[0026] According to the above structure, the current collector 30, which is an integral component, electrically connects the electrode body 10 and the external terminal 20, thereby increasing the volume ratio of the electrode body 10 in the battery cell 1. Furthermore, since the contact areas between the first locking portion 32 and the electrode body 10, and the contact areas between the second locking portion 33 and the electrode body 10, are relatively large, the electrical connection between the electrode body 10 and the external terminal 20 via the current collector 30 can be more stable.

[0027] That is, according to the above structure, the electrode body 10 and the external terminal 20 can be stably electrically connected, and the volume ratio of the electrode body 10 in the battery cell 1 can be increased.

[0028] Furthermore, in this embodiment, the electrode body 10 includes a stacked electrode portion 11 and an electrode foil 12. The stacked electrode portion 11 is formed by stacking a first electrode 11a and a second electrode 11b in a direction orthogonal to the axial direction, wherein one of the first electrode 11a and the second electrode 11b is a positive electrode and the other is a negative electrode. The stacked electrode portion 11 is arranged axially alongside the current collector 30. The electrode foil 12 extends from the portion of the first electrode 11a that does not face the current collector 30. The shaft portion 31 passes through the electrode foil 12.

[0029] According to the above structure, the electrode foil 12 can be electrically connected to the current collector 30 without placing the electrode foil 12 between the stacked electrode portion 11 and the first locking portion 32. Therefore, the distance between the stacked electrode portion 11 and the current collector 30 can also be relatively small. Furthermore, the volume ratio of the electrode body 10 in the battery cell 1 can be further improved.

[0030] Furthermore, in this embodiment, the entire surface of the first locking portion 32 facing the shaft portion 31 in the axial direction is in contact with the electrode body 10. The entire surface of the second locking portion 33 facing the shaft portion 31 in the axial direction is in contact with the external terminal 20.

[0031] According to the above structure, the contact area between the first locking portion 32 and the electrode body 10 and the contact area between the second locking portion 33 and the electrode body 10 can be further increased. Furthermore, the electrical connection between the electrode body 10 and the external terminal 20 can be made more stable.

[0032] Furthermore, in this embodiment, the shaft portion 31 has a cylindrical shape with a central axis along the axial direction. The first locking portion 32 and the second locking portion 33 are formed by riveting and have a circular shape centered on the central axis when viewed from the axial direction.

[0033] According to the above structure, during the above riveting, the first locking part 32 or the second locking part 33 can be stably formed without dispersing stress.

[0034] Furthermore, in this embodiment, the current collector 30 is not soldered to either the electrode body 10 or the external terminal 20.

[0035] According to the above structure, the welding process of the current collector 30 is not required in the manufacturing of the battery cell 1. Furthermore, the battery cell 1 is easier to manufacture, and a cheaper battery cell 1 can be provided. In addition, as described above, even without welding, the electrode body 10 and the external terminal 20 are stably electrically connected based on the relationship between the contact areas and the cross-sectional areas.

[0036] In the description of the above embodiments, the combinable structures can be combined with each other.

[0037] It should be considered that the embodiments disclosed herein are illustrative in all respects and not restrictive. The scope of the invention is not shown in the foregoing description, but is defined by the claims, and is intended to include all modifications within the meaning and scope equivalent to the claims.

[0038] Symbol Explanation

[0039] 1-Storage cell, 10-Electrode body, 11-Layered electrode section, 11a-First electrode, 11b-Second electrode, 11c-Separator, 12-Electrode foil, 20-External terminal, 30-Current collector, 31-Shaft section, 32-First locking section, 33-Second locking section, 40-Outer casing.

Claims

1. A battery cell, characterized in that, have: Electrode body; External terminals; and Current collector, The current collector is composed of an integral component. The current collector includes a shaft portion, a first locking portion, and a second locking portion. The first or second locking portion is formed by riveting. The shaft extends axially through the electrode body and the external terminal. The first locking portion is connected to one axial end of the shaft portion and locks into the electrode body. The second locking portion is connected to the other end of the shaft portion along its axial direction and is locked to the external terminal. The contact area between the first locking portion and the electrode body is greater than the cross-sectional area of ​​the shaft portion along the direction perpendicular to the axial direction. The contact area between the second locking portion and the external terminal is greater than the cross-sectional area.

2. The battery cell according to claim 1, characterized in that, The electrode body includes stacked electrode sections and electrode foils. The stacked electrode section is formed by stacking a first electrode and a second electrode together in a direction orthogonal to the axial direction. One of the first electrode and the second electrode is a positive electrode and the other is a negative electrode. The stacked electrode portion is arranged side by side with the current collector in the axial direction. The electrode foil extends from the portion of the first electrode that does not face the current collector. The shaft portion extends through the electrode foil.

3. The battery cell according to claim 1, characterized in that, In the first locking portion, the entire surface facing the shaft side in the axial direction is in contact with the electrode body. In the second locking portion, the entire surface facing the shaft side in the axial direction is in contact with the external terminal.

4. The battery cell according to any one of claims 1 to 3, characterized in that, The shaft portion has a cylindrical shape with a central axis along the axial direction. The first and second locking portions are riveted together to form a circular shape centered on the central axis when viewed from the axial direction.

5. The battery cell according to any one of claims 1 to 3, characterized in that, The current collector is not soldered to either the electrode body or the external terminal.

Images