battery cell

Abstract

The present invention provides a battery cell with a configuration that can suppress the load on a busbar even if a battery cell swells, when the cell terminals of adjacent battery cells are connected by a busbar. [Solution] This battery cell 1A comprises a cell terminal opening 111h provided in the sealing plate 111 of the outer casing 11, a cell terminal 13 positioned in the cell terminal opening 111h, and an annular displacement gasket 16 positioned between the outer circumferential surface 13m of the cell terminal 13 and the inner circumferential surface 111m of the cell terminal opening 111h in order to mount the cell terminal 13 into the cell terminal opening 111h, wherein the displacement gasket 16 is provided so as to be deformable in a plane including the upper surface 111.

Description

Technical Field

[0001] This technology relates to battery cells.

Background Art

[0002] Battery cells are provided with cell terminals for outputting power externally. Patent Document 1 (Japanese Unexamined Patent Application Publication No. 2010-33940) and Patent Document 2 (Japanese Unexamined Patent Application Publication No. 2010-97818) disclose a configuration in which a cell terminal is assembled with a resin gasket interposed on the upper surface of a metal exterior can constituting the battery cell.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0004] In a battery module in which a plurality of battery cells are stacked, cell terminals of adjacent battery cells are electrically connected by a welding structure using a metal bus bar or a fastening structure using screws.

[0005] When the battery cell is charged, the battery cell bulges, so adjacent battery cells tend to move away from each other. However, in a state where the cell terminals are connected by a bus bar, the bulge of the battery cell is restricted by the bus bar, and there is a risk that a large load is applied to the bus bar.

[0006] This technology was developed to solve the above-mentioned problems, and aims to provide a battery cell that has a configuration that can suppress the load on the busbar even when a battery cell swells, when the cell terminals of adjacent battery cells are connected by a busbar. [Means for solving the problem]

[0007] This technology provides the following battery cells: [1] A battery cell comprising: an electrode body; a rectangular outer casing for housing the electrode body and having an outer surface including a top surface, long sides and short sides; an electrode terminal opening provided on the top surface of the outer casing; an electrode terminal disposed in the electrode terminal opening; and an annular first gasket disposed between the outer circumferential surface of the electrode terminal and the inner circumferential surface of the electrode terminal opening for mounting the electrode terminal in the electrode terminal opening, wherein the first gasket is provided so as to be deformable in a plane including the top surface.

[0008] [2] The battery cell according to [1], comprising an annular second gasket mounted on the outer surface of the electrode terminal and an annular fixing ring mounted on the outer surface of the second gasket, wherein the first gasket is mounted between the outer surface of the fixing ring and the inner surface of the electrode terminal opening.

[0009] [3] The battery cell according to [1] or [2], wherein the first gasket is arranged to be in contact with the outer circumferential surface of the electrode terminal and the inner circumferential surface of the electrode terminal opening.

[0010] [4] The battery cell according to any one of items [1] to [3], wherein the first gasket is circular and annular in shape.

[0011] [5] The battery cell according to any one of [1] to [3], wherein the top surface includes a long side along the long side and a short side along the short side, and the first gasket has an annular shape in which the length in the direction along the short side is longer than the length along the long side.

[0012] [6] The battery cell according to any one of [1] to [5], wherein the first gasket comprises a first annular member made of a resin that is elastically deformable and a second annular member that brings the first gasket into close contact with the outer and inner members. [Effects of the Invention]

[0013] The objective of this technology is to provide a battery cell that has a configuration that can suppress the load on the busbar even when a battery cell swells, when the cell terminals of adjacent battery cells are connected by a busbar. [Brief explanation of the drawing]

[0014] [Figure 1] This is a perspective view showing the configuration of the battery cell in Embodiment 1. [Figure 2] This is an exploded perspective view showing the configuration around the cell terminals of Embodiment 1. [Figure 3] This is a partial cross-sectional view showing the configuration around the cell terminals of Embodiment 1. [Figure 4] This is a partial cross-sectional view showing the battery cells of Embodiment 1 arranged in a row. [Figure 5] This is a perspective view showing the configuration of the battery cell in Embodiment 2. [Figure 6] This is an exploded perspective view showing the configuration around the cell terminals of Embodiment 2. [Figure 7] This is a partial cross-sectional view showing the configuration around the cell terminals of Embodiment 2. [Figure 8] This is a plan view showing the configuration of the cell terminals in Embodiment 3. [Modes for carrying out the invention]

[0015] Embodiments of this technology are described below. The same or corresponding parts are denoted by the same reference numerals, and their descriptions may not be repeated.

[0016] In the embodiments described below, when referring to the number, quantity, etc., unless otherwise specified, the scope of the present technology is not necessarily limited to such number, quantity, etc. In the following embodiments, each component is not necessarily essential to the present technology, unless otherwise specified. The present technology is not necessarily limited to those that exhibit all the effects described in the present embodiment.

[0017] In this specification, the descriptions of "comprise", "include", and "have" are in an open-ended format. That is, when including a certain configuration, other configurations outside the said configuration may or may not be included.

[0018] In this specification, when geometric terms and terms representing positional and directional relationships, such as "parallel", "orthogonal", "oblique 45°", "coaxial", "along", etc. are used, these terms allow for manufacturing errors or slight variations. In this specification, when terms representing relative positional relationships such as "upper side", "lower side", etc. are used, these terms are used to indicate the relative positional relationship in one state, and depending on the installation direction of each mechanism (such as flipping the entire mechanism upside down, etc.), the relative positional relationship can be inverted or rotated at an arbitrary angle.

[0019] In this specification, "battery" is not limited to lithium-ion batteries and may include other batteries such as nickel-metal hydride batteries and sodium-ion batteries. In this specification, "electrode" may be a general term for the positive electrode and the negative electrode.

[0020] The "battery cell" in this specification is used for battery modules and battery packs that can be installed in hybrid electric vehicles (HEV), plug-in hybrid electric vehicles (PHEV), and battery electric vehicles (BEV), etc. The use of the "battery cell" in this specification is not limited to in-vehicle use.

[0021] (Embodiment 1: Battery cell 1A) Referring to Figure 1, the external configuration of battery cell 1A will be described. Battery cell 1A is, for example, a lithium-ion battery.

[0022] The battery cell 1A includes an electrode body 100, a rectangular metal housing 11 (outer casing) that houses the electrode body 100, a cell terminal opening 111h (electrode terminal opening) provided in the sealing plate 111 of the housing 11, a cell terminal 13 (electrode terminal) positioned in the cell terminal opening 111h, and a gas discharge 20.

[0023] The housing 11 has a rectangular parallelepiped shape (square shape) and has the appearance of a battery cell 1A. The housing 11 houses the electrode body 100 and the electrolyte (not shown). The housing 11 is an outer casing having a sealing plate 111 (top surface), a bottom plate 112 (bottom surface), a pair of opposing long sides 121, and a pair of opposing short sides 131.

[0024] The sealing plate 111 faces the bottom plate 112 along a third direction (Z direction) perpendicular to the first direction (X direction) and the second direction (Y direction). The sealing plate 111 and the bottom plate 112 are planes perpendicular to the Z direction.

[0025] The pair of long sides 121 face each other along a second direction (Y direction) perpendicular to the first direction (X direction). The pair of long sides 121 consist of a plane perpendicular to the Y direction. The long sides 121 have the largest area among the multiple sides of the housing 11. The long sides 121 have a rectangular shape when viewed from the Y direction. The long sides 121 have a rectangular shape when viewed from the Y direction, with the X direction being the longitudinal direction and the Z direction being the short direction.

[0026] The sealing plate 111 faces the bottom plate 112 along a third direction (Z direction) perpendicular to the first direction (X direction) and the second direction (Y direction). The sealing plate 111 and the bottom plate 112 are planes perpendicular to the Z direction.

[0027] The sealing plate 111 includes a long side 111a along the long side 121 and a short side 111b along the short side 131, and has a rectangular shape with the long side 111a in the first direction (X direction).

[0028] The cell terminals 13 are arranged side by side along the first direction (X direction) of the sealing plate 111, with one cell terminal 13 functioning as the positive terminal and the other cell terminal 13 functioning as the negative terminal. The two cell terminals 13 are spaced apart from each other in the first direction (X direction).

[0029] In a battery module using multiple battery cells 1A, the battery cells 1A are stacked such that adjacent long sides 121 face each other in the Y direction. As a result, in the Y direction where the multiple battery cells 1A are stacked, the positive and negative terminals are arranged alternately.

[0030] (Peripheral structure of cell terminal 13) The surrounding structure of the cell terminal 13 will be described with reference to Figures 2 and 3. The cell terminal 13, gasket 14 (second gasket), fixing ring 15, and deformed gasket 16 (first gasket) are fitted into the cell terminal opening 111h. All of these components have a circular annular shape. The gasket 14 is fitted to the outer circumferential surface 13m of the cell terminal 13, the fixing ring 15 is fitted to the outer circumferential surface 14m of the gasket 14, and the deformed gasket 16 is fitted between the outer circumferential surface 15m of the fixing ring 15 and the inner circumferential surface 111m of the cell terminal opening 111h.

[0031] On the inner surface of the sealing plate 111, an internal busbar 18, which is electrically connected to the internal electrode body 100, is connected to the cell terminal 13. The internal busbar 18 is insulated from the sealing plate 111 by an insulating material 17.

[0032] (Deformed gasket 16) The deformable gasket 16 includes a first annular member 16a made of resin that can be elastically deformed, and a second annular member 16b having a higher elastic modulus (less deformable) than the first annular member 16a. Examples of materials for the first annular member 16a include acrylonitrile butadiene rubber (NBR), ethylene propylene diene rubber (PDM), silicone rubber, fluorosilicone rubber, hydrogenated nitrile rubber, fluororubber, acrylic rubber, chloroprene rubber, butyl rubber, styrene butadiene rubber, and urethane rubber. In its cross-sectional shape, the first annular member 16a has a recessed shape that opens toward the bottom plate 112. This first annular member 16a primarily serves to ensure airtightness.

[0033] The first annular member 16a has a base 161, an inner edge 162 located on the inner circumference side, and an outer edge 163 located on the outer circumference side.

[0034] The second annular member 16b comprises an inner second annular member 16b1 and an outer second annular member 16b2. For example, the materials used for the inner second annular member 16b1 and the outer second annular member 16b2 can be rolled steel, stainless steel, aluminum, copper, etc. Furthermore, spring-like materials made from various materials can also be used.

[0035] The inner second annular member 16b1 has a hollow annular shape in cross-section. The outer second annular member 16b2 has an L-shaped annular shape in cross-section. The inner second annular member 16b1 is embedded in the inner edge 162 of the first annular member 16a so that half of it is exposed. The outer second annular member 16b2 is entirely embedded in the bottom edge 161 and outer edge 163 of the first annular member 16a. The second annular member 16b primarily serves to ensure tightness and airtightness between the deformed gasket 16 and its inner and outer members.

[0036] Referring to Figure 4, we will now describe the case where battery cells 1A having the aforementioned peripheral structure of the cell terminals 13 are arranged and adjacent cell terminals 13 are connected by an external busbar 30 (when used as a battery module).

[0037] When battery cell 1A is being charged, it expands in the first direction (X direction), causing adjacent battery cells 1A to move away from each other. However, the external busbar 30 cannot expand in the first direction (X direction).

[0038] As a result, a force in the direction of F1 shown in Figure 4 is generated at the cell terminal 13. In this embodiment, since a deformable gasket 16 is provided, it deforms in a direction that absorbs the external force generated at the cell terminal 13. In the case of Figure 4, the deformable gasket 16 located on the inside deforms in a compressive direction. The deformable gasket 16 located on the outside deforms in an elongated direction.

[0039] As described above, when the deformable gasket 16 in this embodiment is used, the deformable gasket 16 is provided so as to be deformable in a plane including the sealing plate 111. This ensures airtightness around the cell terminal 13, while the deformable gasket 16 can absorb the external force on the cell terminal 13 generated from the external busbar 30 by deforming. As a result, the load on the external busbar 30 and the cell terminal 13 can be suppressed without hindering the swelling of the battery cell 1A during charging.

[0040] (Embodiment 2: Battery cell 1B) Referring to Figures 5 to 7, the configuration of the battery cell 1B in Embodiment 2 will be described. As shown in Figure 5, the external appearance of the battery cell 1B in this embodiment is the same as that of the battery cell 1A, and only the peripheral structure of the cell terminal 13 differs from that of the battery cell 1A described above. Therefore, the peripheral structure of the cell terminal 13 will be described here.

[0041] As shown in Figure 6, the cell terminal 13 and the deformed gasket 16 (first gasket) are installed in the cell terminal opening 111h. Specifically, as shown in Figure 7, the deformed gasket 16 is positioned to be in contact with the outer circumferential surface 13m of the cell terminal 13 and the inner circumferential surface 111m of the cell terminal opening 111h. The deformed gasket 16 has the same structure as described in Embodiment 1.

[0042] Even when using the battery cell 1B in this second embodiment, the same effects and advantages as those of the battery cell 1A described in the first embodiment above can be obtained.

[0043] (Embodiment 3: Battery cell 1C) Referring to Figure 8, the configuration of the battery cell 1C in Embodiment 3 will be described. As shown in Figure 8, in this embodiment, when the cell terminal 13 is viewed from above (third direction (Z direction)), the shape of the deformed gasket 16 is not a circular annular shape, but an annular shape in which the length along the short side 111b of the sealing plate 111 is longer than the length along the long side 111a. The shape is not limited to the track shape of an athletics stadium as shown, but may also be elliptical.

[0044] In this way, by making the deformed gasket 16 longer in the X direction than in the Y direction, external forces generated at the cell terminal 13 can be effectively absorbed.

[0045] While embodiments of the present technology have been described above, the embodiments disclosed herein should be considered in all respects to be illustrative and not restrictive. The scope of the present technology is defined by the claims, and all modifications within the meaning and scope equivalent to the claims are intended to be included. [Explanation of Symbols]

[0046] 1A, 1B, 1C Battery cells, 11 Housing (outer can), 13 Cell terminals (electrode terminals), 13m, 14m Outer surface, 14 Gasket (second gasket), 15 Fixing ring, 16 Deformed gasket (first gasket), 16a First annular member, 16b Second annular member, 16b1 Inner second annular member, 16b2 Outer second annular member, 17 Insulating material, 18 Internal busbar, 20 Gas outlet, 30 External busbar, 100 Electrode body, 111 Sealing plate, 111a Long side, 111b Short side, 111m Inner surface, 111h Cell terminal opening (electrode terminal opening), 112 Bottom plate (bottom surface), 121 Long side, 131 Short side, 161 Bottom, 162 Inner side, 163 Outer side.

Claims

1. Electrode body and A rectangular outer container housing the electrode body, having an outer surface including a top surface, a long side surface, and a short side surface, An electrode terminal opening provided on the upper surface of the outer can, An electrode terminal arranged in the electrode terminal opening, To attach the electrode terminal to the electrode terminal opening, an annular-shaped first gasket is disposed between the outer circumferential surface of the electrode terminal and the inner circumferential surface of the electrode terminal opening, Equipped with, The first gasket is provided so as to be deformable in a plane including the upper surface. Battery cell.

2. An annular second gasket is attached to the outer surface of the electrode terminal, An annular fixing ring attached to the outer surface of the second gasket, Includes, The first gasket is fitted between the outer circumferential surface of the fixing ring and the inner circumferential surface of the electrode terminal opening. The battery cell according to claim 1.

3. The first gasket is It is arranged so as to be in contact with the outer circumferential surface of the electrode terminal and the inner circumferential surface of the electrode terminal opening. The battery cell according to claim 1.

4. The first gasket has a circular, annular shape. The battery cell according to claim 1.

5. The upper surface includes a long side along the long side and a short side along the short side, The first gasket has an annular shape in which the length along the short side is longer than the length along the long side. The battery cell according to claim 1.

6. The first gasket is A first annular member made of resin that is elastically deformable, A second annular member that brings the first gasket into close contact with its outer and inner members, A battery cell according to claim 1, including the following:

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