Battery shell and lithium battery

Abstract

The utility model belongs to the technical field of lithium batteries, and particularly relates to a battery shell and a lithium battery, the battery shell comprises a shell body, at least one pair of bulges is arranged on the inner wall of the shell body, and the bulges are arranged at the positions, corresponding to pole piece thinning areas, on the side of a pole lug; by increasing the thickness of the shell body corresponding to the thinning area on the tab side of the battery cell, equivalently increasing the group margin design of the thinning area, the problem that the gap between positive and negative pole pieces of the thinning area relative to a normal area is too large is solved, and the lithium precipitation risk of the thinning area in the long-cycle process is improved.

Description

Technical Field

[0001] The utility model belongs to the technical field of lithium batteries, and specifically relates to a battery shell and a lithium battery. Background Art

[0002] During the cycle of lithium batteries, the kinetic window in the edge area of ​​the pole lug side will be narrower than the kinetic window in other areas due to factors such as edge thinning, large pole piece gap on the pole lug side, high current density on the pole lug side, and increased temperature. In the middle and late stages of the cycle, there is a greater risk of lithium plating due to the continuous reduction of the kinetic window.

[0003] In the related technology, the problem of insufficient edge dynamics in the later stage of the cycle can be alleviated to a certain extent by optimizing the gasket to reduce the thinning and improve the thinned area, but the degree of improvement is limited and cannot be eradicated; using tape to occupy the thinned area and then removing the thinned area by tearing off the tape can effectively improve this problem, but it will greatly increase costs and reduce production efficiency; the improvement of the thinned area only improves the edge area dynamics from the perspective of the edge NP ratio, but it cannot solve the problem that the gap between the positive and negative pole pieces on the ear side is larger than the internal pole piece.

[0004] Therefore, in order to solve the problem that the gap between the positive and negative electrode sheets in the thinned area is too large relative to the normal area, it is necessary to design a new battery casing and lithium battery. Utility Model Content

[0005] The purpose of the utility model is to provide a battery housing and a lithium battery to solve the above technical problems.

[0006] In order to solve the above technical problems, the utility model provides a battery housing, comprising:

[0007] The shell body has at least one pair of protrusions on its inner wall, and the protrusions are arranged at positions on the pole ear side corresponding to the pole piece thinning areas.

[0008] Further, the protrusions are a pair;

[0009] The protrusions are arranged on a pair of inner walls of the shell body arranged opposite to each other, that is,

[0010] One protrusion is arranged on one inner wall of the shell body, and another protrusion is arranged on an inner wall opposite to the inner wall.

[0011] Further, the protrusion is transversely arranged on the inner wall of the shell body;

[0012] The protrusion is arranged close to the top surface of the shell body.

[0013] Further, the protrusions are two pairs;

[0014] A pair of protrusions is arranged on one inner wall of the shell body, and another pair of protrusions is arranged on an inner wall opposite to the inner wall.

[0015] Further, the protrusion is vertically arranged on the inner wall of the shell body;

[0016] There is a gap between the top of the protrusion and the top surface of the shell body;

[0017] The protrusion is arranged close to the corner of the shell body.

[0018] Furthermore, the upper edge of the protrusion is flush with the negative electrode plate of the battery cell.

[0019] Furthermore, the outer wall of the protrusion is a plane or an arc convex surface.

[0020] Furthermore, the thickness of the protrusion ranges from 0.05 mm to 0.2 mm.

[0021] Furthermore, the width of the protrusion is in the range of 5 mm to 15 mm.

[0022] On the other hand, the utility model also provides a lithium battery using the above battery housing, comprising:

[0023] The battery core is arranged in the shell body.

[0024] The beneficial effect of the utility model is that, through the shell body, the inner wall of the shell body is provided with at least one pair of protrusions, and the protrusions are arranged at the position of the thinning area corresponding to the pole piece on the pole ear side; by increasing the thickness of the shell body corresponding to the thinning area on the pole ear side of the battery cell, it is equivalent to increasing the group margin design of the thinning area, thereby solving the problem of excessive gap between the positive and negative pole pieces in the thinning area relative to the normal area, and improving the risk of lithium plating in the thinning area during long cycles.

[0025] Other features and advantages of the utility model will be described in the following description, and partly become apparent from the description, or understood by practicing the utility model. The purpose and other advantages of the utility model are realized and obtained by the structures particularly pointed out in the description and the drawings.

[0026] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, preferred embodiments are given below and described in detail with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the specific implementation methods of the utility model or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0028] Figure 1 This is a schematic diagram of the structure of an optional battery housing of the utility model;

[0029] Figure 2 This is a partial cross-sectional view of an optional battery housing of the present utility model;

[0030] Figure 3 yes Figure 2 The enlarged schematic diagram of part I;

[0031] Figure 4 It is a schematic structural diagram of another optional battery housing of the utility model;

[0032] Figure 5 It is a longitudinal cross-sectional view of another optional battery housing of the utility model;

[0033] Figure 6 yes Figure 5 An enlarged schematic diagram of part D in the middle;

[0034] Figure 7 It is a transverse cross-sectional view of another optional battery housing of the utility model;

[0035] Figure 8 yes Figure 7 Enlarged schematic diagram of part C.

[0036] In the figure:

[0037] 1 is the shell body, 2 is the protrusion. DETAILED DESCRIPTION

[0038] In order to make the purpose, technical solution and advantages of the embodiments of the utility model clearer, the technical solution of the utility model will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the described embodiments are part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0039] like Figures 1 to 8As shown, at least one embodiment provides a battery shell, comprising: a shell body 1, wherein the inner wall of the shell body 1 is provided with at least one pair of protrusions 2, and the protrusions 2 are arranged at positions corresponding to the pole piece thinning areas on the pole ear side; by increasing the thickness of the shell body 1 corresponding to the thinning area on the pole ear side of the battery cell, it is equivalent to increasing the group margin design of the thinning area, thereby solving the problem of excessive gap between the positive and negative pole pieces in the thinning area relative to the normal area, and improving the risk of lithium plating in the thinning area during long cycles.

[0040] The shell body 1 is modified in the direction of setting a protrusion 2 at the position of the pole piece thinning area corresponding to the pole piece on the pole ear side to increase the internal thickness of the shell body 1, and the external size of the shell body 1 can be kept unchanged, which can solve the problem of large gap between the positive and negative pole pieces in the edge thinning area; according to the width of the positive and negative pole pieces in the battery design and the thinning specifications on the pole ear side, the setting position and width of the protrusion 2 are determined; according to the number of battery cell layers and the group margin design, the range of the thickness of the protrusion 2 is confirmed; in this way, the battery cell group margin in the thickened area of ​​the shell body 1 (i.e., the position where the protrusion 2 is set) is higher than that in the normal pole piece area, which has a certain squeezing effect on the thinning area in the later cycle process, thereby reducing the gap between the pole pieces in the thinning area and reducing the risk of lithium deposition in the thinning area.

[0041] One arrangement of the protrusions 2 may be that the protrusions 2 are a pair; the protrusions 2 are arranged on a pair of inner walls of the shell body 1 arranged opposite to each other, that is, one protrusion 2 is arranged on one inner wall of the shell body 1, and the other protrusion 2 is arranged on the inner wall opposite to the inner wall; the protrusions 2 are arranged transversely on the inner wall of the shell body 1; the position where the protrusions 2 are arranged is the thickened area of ​​the shell body 1; the protrusions 2 are arranged close to the top surface of the shell body 1; t is the normal thickness of the shell body 1; T is the thickness of the shell body 1 and the protrusions The sum of the thicknesses of protrusions 2; H is the height from the thickening area to the top surface of the shell body 1; W is the width of the thickening area, that is, the width of protrusion 2; the thickness of protrusion 2 (Tt) is related to the number of battery cell layers, group margin, and pole piece thinning thickness, and the thickness range of protrusion 2 is 0.05mm-0.2mm; the width of large protrusion 2 (W) is related to the width design of the thinning area of ​​the positive and negative pole pieces, and the width range is 5mm-15mm; the height from the thickening area to the top surface of the shell body 1 (H) is related to the battery cell design to ensure that the upper edge of the thickening area is flush with the negative pole piece of the battery cell.

[0042] Another arrangement of the protrusions 2 may be that the protrusions 2 are in two pairs; one pair of protrusions 2 is arranged on an inner wall of one side of the shell body 1, and the other pair of protrusions 2 is arranged on an inner wall opposite to the inner wall; the protrusions 2 are vertically arranged on the inner wall of the shell body 1; there is a gap between the top of the protrusion 2 and the top surface of the shell body 1; the protrusions 2 are arranged close to the corners of the shell body 1; the upper edge of the protrusions 2 is flush with the negative electrode sheet of the battery cell; the thickness (Tt) of the protrusions 2 is related to the number of battery cell layers, group margin, and electrode sheet thinning thickness, and the thickness range of the protrusions 2 is 0.05mm-0.2mm; the width (W) of the large protrusions 2 is related to the width design of the positive and negative electrode sheet thinning area, and the width range is 5mm-15mm; the height (H) from the thickening area to the top surface of the shell body 1 and the edge distance (L) are related to the battery cell design to ensure that the upper edge of the thickening area is flush with the negative electrode sheet of the battery cell.

[0043] Two different configurations of the protrusion 2 can be adapted to different battery structures.

[0044] The outer wall of the protrusion 2 is a plane or an arc convex surface. When the outer wall of the protrusion 2 is an arc convex surface, the thickness of the protrusion 2 can be gradually changed.

[0045] In some other embodiments, a lithium battery using the above-mentioned battery shell is also provided, including: a battery cell, wherein the battery cell is arranged in the shell body 1.

[0046] In summary, the utility model adopts a shell body 1, the inner wall of which is provided with at least one pair of protrusions 2, and the protrusions 2 are arranged at the position of the thinning area corresponding to the pole piece on the pole ear side; it realizes the group margin design of increasing the thickness of the shell body 1 corresponding to the thinning area on the pole ear side of the battery cell, which is equivalent to increasing the thinning area, thereby solving the problem of excessive gap between the positive and negative pole pieces in the thinning area relative to the normal area, and improving the risk of lithium plating in the thinning area during long cycles.

[0047] The various devices selected in this application (components whose specific structures are not described) are all universal standard parts or components known to those skilled in the art, and their structures and principles can be known to those skilled in the art through technical manuals or conventional experimental methods.

[0048] In the description of the embodiments of the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0049] In the description of the present invention, it should be noted that the terms "center", "up", "down", "left", "right", "vertical", "horizontal", "inside", "outside", etc. indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction. Therefore, they cannot be understood as limitations on the present invention.

[0050] Based on the above ideal embodiments of the utility model, the relevant staff can make various changes and modifications without deviating from the technical concept of the utility model through the above description. The technical scope of the utility model is not limited to the content of the specification, and its technical scope must be determined according to the scope of the claims.

Claims

1. A battery housing, characterized in that: include: The shell body has at least one pair of protrusions on its inner wall, and the protrusions are arranged at positions on the pole ear side corresponding to the pole piece thinning areas.

2. The battery housing according to claim 1, wherein: The protrusions are a pair; The protrusions are arranged on a pair of inner walls of the shell body arranged opposite to each other, that is, One protrusion is arranged on one inner wall of the shell body, and another protrusion is arranged on an inner wall opposite to the inner wall.

3. The battery case according to claim 2, characterized in that: The protrusion is arranged transversely on the inner wall of the shell body; The protrusion is arranged close to the top surface of the shell body.

4. The battery case according to claim 1, characterized in that: The protrusions are in two pairs; A pair of protrusions is arranged on one inner wall of the shell body, and another pair of protrusions is arranged on an inner wall opposite to the inner wall.

5. The battery case according to claim 4, characterized in that: The protrusion is vertically arranged on the inner wall of the shell body; There is a gap between the top of the protrusion and the top surface of the shell body; The protrusion is arranged close to the corner of the shell body.

6. The battery case according to claim 1, characterized in that: The upper edge of the protrusion is flush with the negative electrode plate of the battery cell.

7. The battery case according to claim 1, wherein: The outer wall of the protrusion is a plane or an arc convex surface.

8. The battery case according to claim 1, characterized in that: The thickness of the protrusions ranges from 0.05 mm to 0.2 mm.

9. The battery case according to claim 1, characterized in that: The width of the protrusions ranges from 5 mm to 15 mm.

10. A lithium battery using the battery casing according to any one of claims 1 to 9, characterized in that: include: The battery core is arranged in the shell body.

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