Laminated battery cell and battery

Abstract

The utility model discloses a laminated cell and a battery, and belongs to the technical field of lithium batteries, the laminated cell comprises an anode pole piece, a cathode pole piece and a diaphragm, and the anode pole piece, the diaphragm, the cathode pole piece, the diaphragm and the anode pole piece are sequentially stacked to form an annular structure, and extrusion stress exists among the adjacent anode pole piece, the cathode pole piece and the diaphragm. The battery provided by the utility model comprises the laminated battery cell. According to the laminated lithium battery, the anode pole pieces and the cathode pole pieces are mutually stacked to form the annular structure, and an internal stress effect of extrusion can be formed between the adjacent pole pieces, so that the problems that the anode of the existing laminated lithium battery is easy to expand and is not restrained, and the performance of the battery is easy to reduce are solved.

Description

Technical Field

[0001] The utility model relates to the technical field of lithium batteries, and in particular mainly to a laminated battery core and a battery. Background Art

[0002] Stacked lithium batteries are made by stacking multiple layers of positive electrodes, negative electrodes and separators. Compared with wound lithium batteries, stacked lithium batteries make better use of space, have higher energy density, and are less prone to problems such as lithium deposition. They are widely used in various electronic fields.

[0003] The silicon-doped anode of lithium batteries can improve the energy density of the battery. Nowadays, as people's requirements for the energy density of lithium batteries are getting higher and higher, the silicon-doped anode is also getting higher and higher, and even pure silicon anodes are used. However, the expansion rate of pure silicon anodes is very large. The existing laminated lithium batteries only have the outer shell as a constraint, which cannot fully limit the expansion of the anode. Therefore, as the lithium battery is used for a longer time, the expansion of the anode will cause problems such as battery bulging and a sharp decline in performance, and bring various safety hazards.

[0004] In view of this, it is necessary to improve the structure of existing lithium batteries. Utility Model Content

[0005] In view of the deficiencies of the prior art, the utility model provides a laminated battery core and a battery to solve the problem that the anode of the existing laminated lithium battery is easy to expand, unconstrained and easily leads to a decrease in battery performance.

[0006] The utility model discloses a laminated battery cell, comprising an anode electrode sheet, a cathode electrode sheet and a diaphragm, which are stacked in the order of anode electrode sheet-diaphragm-cathode electrode sheet-diaphragm-anode electrode sheet to form an annular structure, and there is extrusion stress between adjacent anode electrode sheets, cathode electrode sheets and diaphragms.

[0007] Preferably, the anode electrode sheet, the cathode electrode sheet and the diaphragm are all rectangular, and the extrusion stress is perpendicular to the surface of the anode electrode sheet and / or the cathode electrode sheet.

[0008] Preferably, the cross-section of the wound battery cell is annular, and the winding axis of the battery cell is parallel to the length direction of the anode electrode sheet and / or the cathode electrode sheet.

[0009] Preferably, the inner circle of the battery core is a hollow structure.

[0010] Preferably, the cross-sectional shape of the battery core is a circular ring, a square ring, a rectangular ring or a regular polygonal ring.

[0011] The utility model discloses a battery, comprising any of the laminated battery cells described above, and also comprising a shell and a cover plate, wherein one end of the shell is provided with an opening, the battery cell is installed inside the shell, and the cover plate is arranged at the opening of the shell.

[0012] Preferably, the shell is an annular structure, and the inner ring of the shell is hollow.

[0013] Preferably, the anode electrode sheet is provided with an anode electrode tab, and the cathode electrode sheet is provided with a cathode electrode tab, the anode electrode tab is connected to the shell, and the cathode electrode tab is connected to the cover plate.

[0014] Preferably, an insulating gasket is provided between the opening of the shell and the cover plate.

[0015] Preferably, the anode electrode sheet and the cathode electrode sheet are both rectangular structures, the anode electrode tab is arranged at one short side of the anode electrode sheet, the cathode electrode tab is arranged at one short side of the cathode electrode sheet, the anode electrode tab is arranged toward the inner side of the shell opening, and the cathode electrode tab is arranged toward the direction of the shell opening.

[0016] The beneficial effects of the utility model are:

[0017] By stacking the anode pole piece and the cathode pole piece on top of each other to form an annular structure, adjacent pole pieces can form an internal stress of compression between each other, so that the pole piece can be restricted by its own restraining force. After the battery has been used for a long time, when the anode pole piece expands, the internal stress of the battery can restrict the expansion of the anode pole piece, which helps to avoid excessive expansion of the anode pole piece and solves the problem of the battery being prone to bulging. Therefore, the utility model solves the problem that the anode of the existing stacked lithium battery is prone to expansion, is not restrained, and easily leads to a decrease in battery performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The drawings described herein are used to provide a further understanding of the present application and constitute a part of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:

[0019] Figure 1 It is a cross-sectional schematic diagram of the laminated battery core of the utility model, and the cross section is a circular ring;

[0020] Figure 2 It is a cross-sectional view of the battery of the present utility model.

[0021] Explanation of the reference numerals: 1. anode electrode sheet; 11. anode electrode tab; 2. cathode electrode sheet; 21. cathode electrode tab; 3. diaphragm; 4. shell; 5. cover plate; 6. insulating gasket. DETAILED DESCRIPTION

[0022] The following will disclose multiple embodiments of the present invention with diagrams. For the purpose of clear description, many practical details will be described together in the following description. However, it should be understood that these practical details should not be used to limit the present invention. In other words, in some embodiments of the present invention, these practical details are not necessary. In addition, for the purpose of simplifying the diagram, some conventional structures and parts will be depicted in a simple schematic manner in the diagram.

[0023] It should be noted that all directional indications such as up, down, left, right, front, back... in the embodiments of the present invention are only used to explain the relative position relationship, movement status, etc. between the components in a certain specific posture as shown in the accompanying drawings. If the specific posture changes, the directional indication will also change accordingly.

[0024] In addition, in the present utility model, the descriptions of "first", "second", etc. are only used for descriptive purposes, and do not specifically refer to the order or sequence, nor are they used to limit the present utility model. They are only used to distinguish between parts or operations described with the same technical terms, and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In addition, the technical solutions between the various embodiments can be combined with each other, but they must be based on the ability of ordinary technicians in this field to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present utility model.

[0025] In order to further understand the content, features and effects of the utility model, the following embodiments are given as examples and described in detail with reference to the accompanying drawings:

[0026] Reference Figure 1 The utility model discloses a laminated battery cell, comprising an anode electrode sheet 1, a cathode electrode sheet 2, and a diaphragm 3, which are stacked in the order of anode electrode sheet 1-diaphragm 3-cathode electrode sheet 2-diaphragm 3-anode electrode sheet 1 to form a ring structure, wherein the anode electrode sheet 1 adopts a silicon-doped anode, and the anode electrode sheet 1, the cathode electrode sheet 2 and the diaphragm 3 are preferably rectangular, and there is extrusion stress between adjacent anode electrode sheets 1, cathode electrode sheets 2 and diaphragm 3, and the direction of the extrusion stress is perpendicular to the surface of the electrode sheets. The extrusion stress enables the battery cell to maintain the ring structure by itself, so that each electrode sheet can be squeezed by adjacent electrode sheets, and when the anode electrode sheet 1 expands, it can be limited by the extrusion stress of the adjacent electrode sheets, thereby constraining the expansion of the anode electrode sheet 1.

[0027] Reference Figure 1Preferably, the cross section of the wound battery cell is a circular ring, the axis of the battery cell is parallel to the length direction of the anode electrode sheet 1 or the cathode electrode sheet 2, and the inner ring of the battery cell is a hollow structure. The cross-sectional shape of the battery cell can be a variety of annular structures with rounded corners, such as a square ring, a rectangular ring, a regular polygonal ring and other shapes.

[0028] Reference Figure 1 and Figure 2 The utility model discloses a battery, comprising the above-mentioned laminated battery cell, and also comprising a shell 4, a cover plate 5 and an insulating gasket 6. The shell 4 is a metal structure, and the shell 4 is wrapped around the outside of the battery cell. The shell 4 is an annular cavity structure with a hollow interior. An opening is provided at one end of the shell 4, and the battery cell is installed in the shell 4 through the opening at the end of the shell 4. The shape of the shell 4 is the same as the shape of the battery cell, and is used to accommodate battery cells of different shapes. Specifically, the shell 4 can be a circular ring, a square ring, a rectangular ring, a regular polygonal ring, etc. The inner ring of the shell 4 is a hollow structure, which is beneficial to improving the heat dissipation performance of the battery; an anode pole ear 11 is provided at one short side of the anode pole piece 1, and a cathode pole ear 21 is provided at one short side of the cathode pole piece 2. The anode pole ear 11 is all facing the inner side of the opening of the shell 4, and the cathode pole ear 21 is all facing the opening of the shell 4. The anode pole ear 11 is welded and fixed to the inner bottom of the shell 4, so that the shell 4 as a whole forms the negative electrode of the battery.

[0029] Reference Figure 1 and Figure 2 The cover plate 5 is covered at the opening of the shell 4, and the cathode ear 21 is fixedly connected to the cover plate 5 by welding. The cover plate 5 is a metal ring sheet whose shape matches the cross-section of the shell 4 and the opening shape of the shell 4. The cover plate 5 serves as the positive electrode of the battery. In order to insulate the cover plate 5 from the shell 4, an insulating gasket 6 is provided between the cover plate 5 and the opening of the shell 4. The insulating gasket 6 forms electrical insulation between the cover plate 5 and the top of the opening of the shell 4, thereby preventing the battery from short circuiting.

[0030] The implementation principle and beneficial effect of the utility model are that, by stacking the anode pole piece 1 and the cathode pole piece 2 on each other to form an annular structure, adjacent pole pieces can form an internal stress of extrusion between each other, so that the pole pieces can be restricted by their own restraining force. After the battery has been used for a long time, when the anode pole piece 1 expands, the internal stress of the battery can limit the expansion of the anode pole piece 1, which is beneficial to avoid excessive expansion of the anode pole piece 1 and solves the problem that the battery is prone to bulging. Therefore, the utility model solves the problem that the anode of the existing stacked lithium battery is easy to expand, unconstrained and easily leads to a decrease in battery performance.

[0031] The above is only an embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the scope of the claims of the present invention.

Claims

1. A laminated battery cell, characterized in that: The invention comprises an anode electrode sheet (1), a cathode electrode sheet (2) and a diaphragm (3), which are stacked in the order of anode electrode sheet (1) - diaphragm (3) - cathode electrode sheet (2) - diaphragm (3) - anode electrode sheet (1) to form an annular structure, and there is a compressive stress between adjacent anode electrode sheets (1), cathode electrode sheets (2) and diaphragms (3).

2. The laminated battery cell according to claim 1, characterized in that: The anode electrode sheet (1), the cathode electrode sheet (2) and the diaphragm (3) are all rectangular, and the extrusion stress is perpendicular to the surface of the anode electrode sheet (1) and / or the cathode electrode sheet (2).

3. The laminated battery cell according to claim 2, characterized in that: The cross-section of the wound battery cell is annular, and the winding axis of the battery cell is parallel to the length direction of the anode electrode sheet (1) and / or the cathode electrode sheet (2).

4. The laminated battery cell according to claim 1, characterized in that: The inner circle of the battery core is a hollow structure.

5. The laminated battery cell according to claim 1, characterized in that: The cross-sectional shape of the battery core is a circular ring, a square ring, a rectangular ring or a regular polygonal ring.

6. A battery, characterized in that: It comprises the laminated battery cell according to any one of claims 1 to 5, and also comprises a shell (4) and a cover plate (5), wherein one end of the shell (4) is provided with an opening, the battery cell is installed inside the shell (4), and the cover plate (5) is covered at the opening of the shell (4).

7. The battery according to claim 6, characterized in that The shell (4) is an annular structure, and the inner ring of the shell (4) is hollow.

8. The battery according to claim 6, characterized in that The anode pole piece (1) is provided with an anode pole ear (11), and the cathode pole piece (2) is provided with a cathode pole ear (21). The anode pole ear (11) is connected to the shell (4), and the cathode pole ear (21) is connected to the cover plate (5).

9. The battery according to claim 6, characterized in that An insulating gasket (6) is provided between the opening of the shell (4) and the cover plate (5).

10. The battery according to claim 8, characterized in that The anode electrode sheet (1) and the cathode electrode sheet (2) are both rectangular structures; the anode electrode ear (11) is arranged at a short side of the anode electrode sheet (1), and the cathode electrode ear (21) is arranged at a short side of the cathode electrode sheet (2); the anode electrode ear (11) is arranged toward the inner side of the opening of the shell (4), and the cathode electrode ear (21) is arranged toward the direction of the opening of the shell (4).

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