Secondary battery

Abstract

The present application relates to a secondary battery. In the secondary battery, a convex portion protruding toward the other side is annularly provided in a region on the outer side in the radial direction of a first electrolyte injection port on a sealing plate, an elastic region capable of elastically deforming is included in a region of a surface on the side in contact with the sealing plate including the convex portion, the sealing member is maintained in an open state in which a gap is generated between the sealing member and the sealing plate by compressing the elastic region by applying a pressing force to the elastic region from the first electrolyte injection port side, and the sealing of the first electrolyte injection port is maintained only by the elastic force of the elastic region by releasing the pressing force and releasing the compression of the elastic region based on the pressing force. According to the secondary battery, the internal pressure in the outer can can be easily reduced at any time.

Description

Technical Field

[0001] This technology relates to secondary batteries. Background Technology

[0002] Regarding the structure of secondary batteries, a technology for having an electrolyte injection port for injecting electrolyte into the interior of the outer casing of a secondary battery is disclosed in Chinese Utility Model No. 221176555, Japanese Patent Application Publication No. 09-288999, Japanese Patent Application Publication No. 2001-110388, Japanese Patent Application Publication No. 2014-170648, and US Patent Publication No. 2024 / 0128609.

[0003] In the conventional structure of secondary batteries, it is known that the internal pressure inside the outer casing of the secondary battery will increase towards the end of its lifespan.

[0004] In the construction of secondary batteries, the internal components such as electrodes and electrolyte need to be sealed and isolated from the external environment of the secondary battery. Once the outer can of the secondary battery is sealed, it cannot be opened again. Therefore, even if the internal pressure inside the outer can rises at the end of the battery's life, it cannot be depressurized. Summary of the Invention

[0005] The purpose of this technology is to provide a secondary battery with a structure that can easily reduce the internal pressure inside the outer canister at any time.

[0006] This technology provides the following secondary batteries.

[0007] [1] A secondary battery comprising: an electrode body; an outer can having an opening; and a sealing plate, the sealing plate receiving the electrode body inside the outer can and sealing the opening, wherein the sealing plate is provided with a first electrolyte injection port for injecting electrolyte into the interior of the outer can, the sealing plate having a sealing member, the sealing member being supported on the inner side of the sealing plate in the outer can by a support member disposed such that it covers the first electrolyte injection port from the inside, wherein either the sealing plate or the sealing member is provided with a first electrolyte injection port. The outer region in the radial direction is provided with a protrusion having an annular shape protruding to the other side. On the side of the sealing member that contacts the sealing plate, the region including the protrusion includes an elastic region capable of elastic deformation. The sealing member applies pressure to the elastic region from the first electrolyte injection port side, thereby compressing the elastic region and maintaining an open state with a gap between the sealing member and the sealing plate. By releasing the pressure, the compression of the elastic region based on the pressure is released, and the seal of the first electrolyte injection port is maintained solely by the elasticity of the elastic region.

[0008] [2] According to the secondary battery described in [1], the protrusion is disposed on the sealing plate.

[0009] [3] According to the secondary battery described in [2], the protrusion is made of the same material as the sealing plate.

[0010] [4] The secondary battery according to any one of [1] to [3], wherein the sealing member is made of a single elastic material.

[0011] [5] The secondary battery according to any one of [1] to [3], wherein the sealing member includes a first region constituting the elastic region and a second region with a hardness greater than that of the first region, wherein the region of the second region facing the first electrolyte injection port is exposed.

[0012] [6] The secondary battery according to any one of [1] to [5], wherein the support member is provided with a second electrolyte injection port communicating with the interior of the outer can.

[0013] [7] The secondary battery according to any one of [1] to [6], wherein the support member is made of the same material as the sealing plate.

[0014] The foregoing and other objects, features, aspects and advantages of the present invention will become clear from the following detailed description relating to the invention, which is understood in conjunction with the accompanying drawings. Attached Figure Description

[0015] Figure 1 This is a perspective view of the square secondary battery according to Embodiment 1.

[0016] Figure 2 This is a partial longitudinal sectional view showing the structure (sealed state) of the first electrolyte injection port in Embodiment 1.

[0017] Figure 3 This is a plan view taken from the inside of the sealing plate, showing the arrangement of the protrusions provided around the first electrolyte injection port in Embodiment 1.

[0018] Figure 4 This is a partial longitudinal sectional view showing the structure (open state) of the first electrolyte injection port in Embodiment 1.

[0019] Figure 5 This is a longitudinal sectional view showing another way of the sealing member of Embodiment 1.

[0020] Figure 6 This is a longitudinal sectional view showing another way of the sealing member of Embodiment 1.

[0021] Figure 7This is a longitudinal sectional view showing another way of the sealing member of Embodiment 1.

[0022] Figure 8 This is a longitudinal sectional view showing another way of the sealing member of Embodiment 1.

[0023] Figure 9 This is a longitudinal sectional view showing another way of the sealing member of Embodiment 1.

[0024] Figure 10 This is a longitudinal sectional view showing another way of the sealing member of Embodiment 1.

[0025] Figure 11 This is a partial longitudinal sectional view showing the structure (sealed state) of the first electrolyte injection port in Embodiment 2.

[0026] Figure 12 yes Figure 11 Sectional view along line XII-XII in the middle.

[0027] Figure 13 This is a longitudinal sectional view showing the assembly of the sealing member according to Embodiment 2.

[0028] Figure 14 This is a partial cross-sectional view showing the structure (open state) of the first electrolyte injection port in Embodiment 2.

[0029] Figure 15 This is a longitudinal sectional view showing another way of the sealing member of embodiment 2.

[0030] Figure 16 This is a cross-sectional view showing another way of the sealing member in Embodiment 2.

[0031] Figure 17 This is a longitudinal sectional view showing another way of the sealing member of embodiment 2. Detailed Implementation

[0032] The embodiments of this technology will be described below. Furthermore, sometimes the same or equivalent parts are labeled with the same reference numerals without repeating their description.

[0033] In the embodiments described below, when numbers, quantities, etc., are mentioned, the scope of the present technology is not necessarily limited to those numbers, quantities, etc., unless specifically stated otherwise. In the embodiments described below, each constituent element is not essential to the present technology unless specifically stated otherwise.

[0034] In this specification, terms such as "comprise," "include," and "have" are open-ended. That is, when a structure is included, other structures besides that structure may be included, or they may not be included. This technology is not limited to the effects mentioned in this embodiment.

[0035] In this specification, when using geometric terms and terms indicating positional and directional relationships, such as "parallel," "orthogonal," "tilted at 45°," "coaxial," and "along," these terms allow for errors or slight variations. In this specification, when using terms indicating relative positional relationships such as "upper side" and "lower side," these terms are used to indicate relative positional relationships in a given state. By adjusting the orientation of each mechanism (e.g., by flipping the entire mechanism up or down), the relative positional relationships can be flipped or rotated to any angle.

[0036] In this specification, "secondary battery" is not limited to lithium-ion batteries, but may include other secondary batteries such as nickel-metal hydride batteries and sodium-ion batteries. In this specification, "electrode" can be collectively referred to as the positive electrode and the negative electrode.

[0037] In the accompanying drawings, relative to the square outer shape of the secondary battery, the width direction (left-right direction on the paper) is designated as the X direction, and the height direction (up-down direction on the paper) is designated as the Z direction. The X, Y, and Z directions are orthogonal to each other. For ease of understanding of the invention, there are parts in the accompanying drawings where the dimensions of each structure have been changed from the actual dimensions.

[0038] (Implementation method 1: Secondary battery 1)

[0039] Reference Figure 1 As an example of a secondary battery in this embodiment, the structure of a square secondary battery will be described. The secondary battery 1 includes a battery casing 100, an electrode body 200, a first electrode 111 (positive terminal), and a second electrode 112 (negative terminal).

[0040] The battery casing 100, serving as an outer packaging can, comprises a square, bottomed, cylindrical outer packaging can 110 with an opening 110h, and a sealing plate 120 that seals the opening 110h of the outer packaging can 110. The outer packaging can 110 and the sealing plate 120 are preferably made of metal, preferably aluminum or an aluminum alloy. The outer packaging can 110 preferably has a width of 30 mm or more, a length of 300 mm or more, and a plate thickness of 0.65 mm or less. The sealing plate 120 preferably has a width of 30 mm or more, a length of 300 mm or more, and a thickness of 2 mm or less.

[0041] A first electrolyte injection port 10 is provided on the sealing plate 120. Electrolyte is injected into the battery casing 100 through the first electrolyte injection port 10. In this embodiment, the secondary battery 1 is provided with a sealing member 20 for sealing the first electrolyte injection port 10.

[0042] Reference Figures 2 to 4 The sealing member 20 is housed within a support member 30 located inside the outer container 110 of the sealing plate 120, in a manner that covers the first electrolyte injection port 10 from the inside. The support member 30 includes a cylindrical portion 30a, a bottom portion 30b, and a flange portion 30f. The flange portion 30f is fixed to the sealing plate 120 using a laser LS or similar method. A plurality of second electrolyte injection ports 30h communicating with the interior of the outer container 110 are provided at the bottom 30b of the support member 30. The support member 30 can be made of the same material as the sealing plate 120. Furthermore, it is not limited to the same material as the sealing plate 120, as long as the material is resistant to electrolyte.

[0043] The opening diameter of the first electrolyte injection port 10 depends on the capacity of the secondary battery 1. The larger the opening diameter, the greater the amount of electrolyte injected per unit time, but it is preferably 1.0 mm or more.

[0044] The inner diameter (D21) of the cylindrical portion 30a of the support member 30 is preferably 0.5 mm or more greater than the outer diameter of the sealing member 20 (D11). The outer diameter (D22) of the cylindrical portion 30a is preferably 0.2 mm or more greater than the inner diameter (D21) of the cylindrical portion 30a. The outer diameter (D23) of the flange portion 30f of the support member 30 is preferably 2 mm greater than the outer diameter (D22) of the cylindrical portion 30a. Furthermore, the width of the flange portion 30f is preferably 1.0 mm or less.

[0045] The inner diameter of the second electrolyte injection port 30h located at the bottom 30b is preferably larger than the total opening area of ​​the first electrolyte injection port 10, and the number of ports is preferably one or more. The second electrolyte injection port 30h is preferably located in an area at the bottom 30b not covered by the sealing member 20. Alternatively, the second electrolyte injection port 30h may be located in the cylindrical portion 30a. The shape of the second electrolyte injection port 30h can be arbitrary.

[0046] In this embodiment, the sealing member 20 is made of a single elastic material capable of elastic deformation. The sealing member 20 preferably has chemical resistance and uses an elastomeric resin or other elastic component. The sealing member 20 has a cylindrical shape. The outer diameter of the sealing member 20 is preferably 3.0 mm or more and [thickness of the secondary battery 1 (Y direction) - (thickness of the outer can 110 × 2)] mm or less. The height of the sealing member 20 is preferably 1.0 mm or more and 20.0 mm or less.

[0047] A protrusion 130b, having an annular shape and protruding toward the sealing member 20, is provided in the region outside the first electrolyte injection port 10 in the radial direction of the sealing plate 120. The protrusion 130b is provided in the region including the surface (elastic region) of the sealing member 20 facing the sealing plate 120. In this embodiment, the protrusion 130b is integrally formed from the same material as the sealing plate 120.

[0048] In this embodiment, the protrusion 130b is made of the same material as the sealing plate 120 (integrated molding), but it can also have a different structure and be made of a different material than the sealing plate 120 (e.g., the same material as the sealing member 20). Preferably, it is a combination of materials that are in close contact with the sealing plate 120 to ensure sealing performance without being glued or fixed to the sealing member 20.

[0049] In this embodiment, the shape (cross-sectional shape) of the protrusion 130b is semi-circular, but it is not limited to this cross-sectional shape and various shapes can be used. Considering the shape of the contact area with the sealing member 20, from the viewpoint of emphasizing the sealing area, the sealing area increases in the order of (small) triangle < semi-circle < trapezoidal / quadrilateral (large). On the other hand, from the viewpoint of emphasizing the sealing surface pressure, the sealing surface pressure decreases in the order of (large) triangle > semi-circle > trapezoidal / quadrilateral (small). The shape (cross-sectional shape) of the protrusion 130b is appropriately selected according to the capacity of the secondary battery 1.

[0050] Reference Figure 3 The outer diameter (D31) of the protrusion 130b (mm) only needs to satisfy [outer diameter (D31) > inner diameter (D32) ≥ diameter of the first electrolyte injection port 10] (mm). The inner diameter (D32) of the protrusion 130b (mm) only needs to satisfy [inner diameter (D32) < outer diameter (D31) ≤ diameter of the upper surface of the sealing member 20] (mm). The protrusion height (H1) of the protrusion 130b can be 0.05 (mm) ≤ H1 ≤ 1.0 mm. For convenience, Figure 3 The single-dotted line diagram shows the configuration position of the sealing member 20.

[0051] Reference Figure 4 The sealing member 20 is compressed by applying pressure to the sealing member 20 from the first electrolyte injection port 10 using a clamp 50 or the like, thereby maintaining the sealing member 20 in an open state with a gap between the sealing member 20 and the sealing plate 120. As a result, electrolyte can be injected into the interior of the outer packaging tank 110 through the first electrolyte injection port 10 and the second electrolyte injection port 30h (arrow F in the figure). Moreover, the internal pressure inside the outer packaging tank 110 can be easily reduced at any time.

[0052] On the other hand, by releasing the pressing pressure, the compression of the sealing member 20 based on the pressing pressure is released, and the seal of the first electrolyte injection port 10 is maintained only by the elasticity of the sealing member 20. Figure 2 (as shown in the diagram). Therefore, when the sealing member 20 is housed inside the support member 30, it is preferable to pre-deform the sealing member 20 elastically to a certain extent before housing it.

[0053] Reference Figures 5 to 10 The shape of the sealing member 20 is not limited to the cylindrical shape described above; it can also be a barrel-shaped sealing member 20A (see reference). Figure 5 ), centrally narrowed sealing member 20B (refer to) Figure 6 ), a sealing member 20C with a truncated cone shape and opposite sides of the large base (refer to) Figure 7 ), a sealing member 20D with a truncated cone shape and opposite sides of the small base (refer to) Figure 8 A truncated cone-shaped sealing member 20E (with the smaller base side facing the first electrolyte injection port 10) (refer to...) Figure 9 ), and a frustum-shaped sealing member 20F (refer to) with the base side facing the first electrolyte injection port 10. Figure 10 Any shape from the list.

[0054] Barrel-shaped sealing member 20A, and truncated cone-shaped sealing member 20C with opposite sides of the large base (see reference). Figure 7 ), and a truncated cone-shaped sealing member 20E (with the smaller base side opposite to the first electrolyte injection port 10) (refer to Figure 9 It can ensure a greater surface pressure on the protrusion 130b and reduce the pressure on the sealing member during electrolyte injection.

[0055] On the other hand, the centrally narrowed sealing member 20B (see reference) Figure 6 ), a sealing member 20D with a truncated cone shape and opposite sides of the small base (refer to) Figure 8 A truncated cone-shaped sealing member 20F (with the large base side facing the first electrolyte injection port 10) (refer to...) Figure 10 It can reduce the pressure on the sealing components during electrolyte injection and can ensure a larger sealing area.

[0056] In the secondary battery 1 of this embodiment, the sealing member 20 is configured to selectively maintain a sealed state of the first electrolyte injection port 10 and an open state of the first electrolyte injection port 10.

[0057] Therefore, when electrolyte is injected into the first electrolyte injection port 10, the sealing member 20 can be elastically deformed to easily inject the electrolyte into the interior of the outer tank 110 through the first electrolyte injection port 10 and the second electrolyte injection port 30h. Moreover, the interior of the outer tank 110 of the secondary battery 1 can be operated at any time until the end of the life of the secondary battery 1, so it is easy to replenish the electrolyte and reduce the internal pressure caused by the release of gas inside the outer tank 110.

[0058] (Implementation Method 2)

[0059] Reference Figures 11 to 14 The structure of the secondary battery in Embodiment 2 will be described below. The basic structure of the secondary battery in Embodiment 2 is the same as that of the secondary battery 1 in Embodiment 1 described above. The difference lies in the structure of the sealing member 20G. Therefore, the structure of the sealing member 20G will be described below.

[0060] Reference Figures 11 to 13 In Embodiment 1 described above, the sealing member is made of a single elastic material capable of elastic deformation. On the other hand, in this embodiment, the sealing member 20G, on the side in contact with the sealing plate 120, includes a first region 20X constituting an elastic region capable of elastic deformation and a second region 20Y with a hardness greater than that of the first region 20X in the area including the protrusion 130b. The second region 20Y faces the first electrolyte injection port 10.

[0061] For example, EPDM rubber with a hardness of 70 [type A hardness tester] is used as the material for Zone 1, 20X. Polyphenylene sulfide (PPS) with a hardness of 120 [Rockwell hardness (R scale)] is used as the material for Zone 2, 20Y.

[0062] The second region 20Y includes: a first cylindrical portion 20Y1 embedded in the first region 20X and including a region (exposed region) facing the first electrolyte injection port 10; and a second cylindrical portion 20Y2 located in the first region 20X and having a larger diameter than the first cylindrical portion 20Y1. The first cylindrical portion 20Y1 is surrounded by the second region 20Y. The shape of the support member 30 is the same as in Embodiment 1 described above.

[0063] Reference Figure 14The sealing member 20G is compressed by applying pressure to its first cylindrical portion 20Y1 from the first electrolyte injection port 10 using a clamp 50, thereby maintaining an open state with a gap between the sealing member 20G and the sealing plate 120. As a result, electrolyte can be injected into the interior of the outer packaging tank 110 through the first electrolyte injection port 10 and the second electrolyte injection port 30h (arrow F in the figure). Furthermore, the internal pressure inside the outer packaging tank 110 can be easily reduced at any time.

[0064] On the other hand, by releasing the pressing pressure, the compression of the sealing member 20G based on the pressing pressure is released, and the seal of the first electrolyte injection port 10 is maintained only by the elasticity of the sealing member 20G. Figure 2 (as shown in the diagram). Therefore, when the sealing member 20 is housed inside the support member 30, it is preferable to pre-deform the sealing member 20 elastically to a certain extent before housing it.

[0065] Thus, the sealing member 20G includes a first region 20X and a second region 20Y with a hardness greater than that of the first region 20X, the second region 20Y having a structure facing the first electrolyte injection port 10. As a result, the region that will be externally deformed (the second region 20Y) and the region that performs the sealing (the first region 20X) are set in different positions.

[0066] According to this structure, rigidity is ensured at the portion (second region 20Y) where deformation of the sealing member 20G is imparted from the outside using a clamp, making elastic deformation at the sealing portion (first region 20X) easier. As a result, deformation of the sealing member 20G can be easily imparted from the outside, and sufficient sealing performance can be ensured.

[0067] In addition, refer to Figure 15 In the above description, the structure in which the area of ​​the first cylindrical portion 20Y1 of the second region 20Y facing the first electrolyte injection port 10 is exposed (not covered by the first region 20X) was described. However, even if there is an area in the first cylindrical portion 20Y1 of the second region 20Y that is not exposed to the first region 20X, as long as the thickness L1 of the first region 20X is smaller than the height H1 of the protrusion 130b, there may be a portion in the first cylindrical portion 20Y1 facing the first electrolyte injection port 10 that is covered by the first region 20X.

[0068] This is because if the thickness of the first region 20X (the thickness of the region opposite to the first electrolyte injection port 10) located in the area where the load is applied from the outside is smaller than the amount of compression of the first region 20X (the height H1 of the protrusion 130b) when sealing, the first electrolyte injection port 10 can be reliably sealed by the first region 20X.

[0069] Moreover, such as Figure 16 As shown, in the face facing the first electrolyte injection port 10, as long as the second region 20Y does not protrude more than the first region 20X, the second region 20Y can also be exposed from the first region 20X on the side.

[0070] Furthermore, the above description illustrates the case where the annular protrusion 130b is provided on the sealing plate 120 side, but it can also be done as follows: Figure 17 As shown in the sealing member 20G, an annular protrusion 20b is provided on the side of the first region 20X facing the sealing plate 120.

[0071] Embodiments of the present invention have been described, but should be considered as illustrative in all respects and not restrictive. The scope of the invention is set forth in the claims and is intended to include all modifications within the scope and equivalent meaning of the claims.

Claims

1. A secondary battery comprising: an electrode body; an outer can having an opening; and a sealing plate that houses the electrode body inside the outer can and seals the opening, wherein... The sealing plate is provided with a first electrolyte injection port for injecting electrolyte into the interior of the outer container. The sealing plate has a sealing component. The sealing member is supported on the inner side of the outer can of the sealing plate by a support member arranged to cover the first electrolyte injection port from the inside. In either the sealing plate or the sealing member, a protrusion with an annular shape protruding towards the other side is provided in the region outside the first electrolyte injection port in the radial direction. The sealing member, on the side in contact with the sealing plate, includes an elastic region capable of elastic deformation in the area including the protrusion. The sealing member applies pressure to the elastic region from the first electrolyte injection port side, thereby compressing the elastic region and maintaining an open state with a gap between the sealing member and the sealing plate. By releasing the pressure, the compression of the elastic region based on the pressure is released, and the first electrolyte injection port is maintained sealed only by the elasticity of the elastic region.

2. The secondary battery according to claim 1, wherein, The protrusion is provided on the sealing plate.

3. The secondary battery according to claim 2, wherein, The protrusion is made of the same material as the sealing plate.

4. The secondary battery according to claim 1, wherein, The sealing component is made of a single elastic material.

5. The secondary battery according to claim 1, wherein, The sealing member includes a first region constituting the elastic region and a second region with a hardness greater than that of the first region. The area of ​​the second region facing the first electrolyte injection port is exposed.

6. The secondary battery according to claim 1, wherein, The supporting member is provided with a second electrolyte injection port that communicates with the interior of the outer tank.

7. The secondary battery according to claim 1, wherein, The supporting member is made of the same material as the sealing plate.

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