Pole piece, battery cell and battery

Abstract

The utility model relates to the technical field of batteries, particularly provides a pole piece, and aims to solve the problem that the end part of the conventional pole piece is easy to fold when the pole piece is used in a battery. In order to achieve the purpose, the utility model provides the pole piece which comprises a conducting layer and an active substance layer arranged on the conducting layer, and the conducting layer is provided with a protruding part at a first side of a first end part. According to the present invention, the protruding portion is arranged on the first side of the first end portion of the conductive layer, such that after the pole piece is wound into the winding core, the protruding portion can be folded to abut against the end surface of the battery cell so as to effectively enhance the structural stability of the battery cell and prevent the occurrence of the safety accident caused by the folding of the end portion in the first direction when the pole piece is used in the battery.

Description

Technical Field

[0001] The utility model relates to the technical field of batteries, and specifically provides a pole piece, a battery core and a battery. Background Art

[0002] With the rapid development of new energy vehicles, the technology of power batteries has also been rapidly improved.

[0003] The existing power batteries are mainly lithium batteries, which include square shell batteries and cylindrical batteries. The cylindrical battery includes a shell and a battery cell contained in the shell. The battery cell is mainly formed by winding the positive and negative electrode sheets and the separator between the positive and negative electrode sheets into a cylinder. However, when the power battery is in use, the battery cell will shake in the shell, which will cause the ends of the positive and negative electrode sheets in the length direction to be easily folded, affecting the structural stability of the battery cell, and even causing the battery cell to short-circuit and other events that affect battery safety.

[0004] Therefore, this field needs a new technical solution to solve the above problems. Utility Model Content

[0005] The utility model aims to solve the above technical problem, that is, to solve the safety problem caused by the folding of the end of the existing pole piece in the length direction.

[0006] In a first aspect, the utility model provides a pole piece, comprising a conductive layer and an active material layer arranged on the conductive layer, wherein the conductive layer is provided with a protrusion on a first side of a first end portion.

[0007] In a preferred technical solution of the above-mentioned pole piece, the conductive layer further includes a plurality of pole tabs, and the plurality of pole tabs are arranged at intervals on the first side.

[0008] In the preferred technical solution of the above-mentioned pole piece, the pole ear is rectangular or trapezoidal.

[0009] In the preferred technical solution of the above-mentioned pole piece, two protrusions are provided and located at both ends of the pole piece.

[0010] In the preferred technical solution of the above-mentioned pole piece, the protrusion is rectangular.

[0011] In a preferred technical solution of the above-mentioned pole piece, the protrusion includes a first end surface, the conductive layer includes a second end surface, and the first end surface is flush with the second end surface.

[0012] In the preferred technical solution of the above-mentioned pole piece, in the second direction, the size of the pole ear is h 1 , the size of the protrusion is h 2 , where 0.4≤h 2 / h 1 ≤0.6.

[0013] Those skilled in the art will appreciate that the pole piece of the present invention has a protrusion on the first side of the first end so that after the pole piece is wound into a winding core, the protrusion can be folded over to rest against the end face of the battery cell, thereby effectively preventing the end of the pole piece in the first direction from being folded over and affecting the structural stability and causing a safety accident.

[0014] In a second aspect, the utility model further provides a battery cell, comprising a wound first pole piece, a diaphragm and a second pole piece, wherein the first pole piece or the second pole piece is the pole piece described in any one of the first aspect, and the protrusion is in contact with the end face of the battery cell.

[0015] In a preferred technical solution of the above battery, the pole lug of the first pole sheet and the pole lug of the second pole sheet are arranged on both sides of the battery cell.

[0016] In a third aspect, the utility model further provides a battery, comprising the battery cell described in any one of the second aspects. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The preferred embodiments of the present invention are described below in conjunction with the accompanying drawings, in which:

[0018] Figure 1 It is an expanded view of the pole piece of the utility model;

[0019] Figure 2 yes Figure 1 The cross-sectional view of the pole piece of the utility model along the cc line is shown;

[0020] Figure 3 It is a cross-sectional view of the battery cell of the utility model;

[0021] Figure 4 It is a top view of the battery core of the utility model.

[0022] Reference numerals:

[0023] 1. Pole piece; 11. Conductive layer; 12. Pole ear; 13. Protrusion; 14. Active material layer; 15. First end; 16. First side; 2. Diaphragm; 10. Battery cell; 1', first pole piece; 1", second pole piece; a, first end face; b, second end face. DETAILED DESCRIPTION

[0024] The preferred embodiments of the present invention are described below with reference to the accompanying drawings. Those skilled in the art should understand that these embodiments are only used to explain the technical principles of the present invention and are not intended to limit the scope of protection of the present invention. For example, although the battery of the present invention is described in the specification as a blade battery, the technical solution of the present invention is not limited to this. Those skilled in the art can apply the technical solution in the present invention to other types of battery structures as needed, and such changes to the application object do not deviate from the principle and scope of the present invention.

[0025] It should be noted that in the description of the present invention, the terms "upper", "lower", "left", "right", "inner", "outer", "front", "back" and the like indicating directions or positional relationships are based on the directions or positional relationships shown in the drawings, which are only for the convenience of description, and do not indicate or imply that the device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation of the present invention. In addition, the terms "first" and "second" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0026] In addition, it should be noted that in the description of the present invention, unless otherwise clearly specified and limited, the terms "connection", "setting" and "installation" 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, a direct connection, or an indirect connection through an intermediate medium. For those skilled in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0027] See first Figure 1 and Figure 2 , the pole piece 1 of the utility model is described.

[0028] See also Figure 1 and Figure 2 As shown, the pole piece 1 of the present invention includes a conductive layer 11 and an active material layer 14 disposed on the conductive layer 11 .

[0029] Furthermore, the electrode 1 can be a positive electrode or a negative electrode, and can be selected and set as needed. When the electrode 1 is a positive electrode, the conductive layer 11 is an aluminum plate, and when the electrode 1 is a negative electrode, the conductive layer 11 is a copper plate. The above is the prior art and will not be repeated here.

[0030] Furthermore, the active material layer 14 is disposed on the conductive layer 11 . Preferably, the active material layer 14 may be provided in two layers and located on both sides of the conductive layer 11 . In other embodiments, the active material layer 14 may be provided in only one layer and located on one side of the conductive layer 11 .

[0031] Active material layer 14 is formed by coating on conductive layer 11 .

[0032] Furthermore, the conductive layer 11 further includes a tab 12 , which is disposed on one side of the conductive layer 11 in the second direction y, namely, the first side 16 . Furthermore, the tab 12 and the conductive layer 11 may be integrally or separately disposed.

[0033] Furthermore, one or more electrode tabs 12 may be provided. When more than one electrode tab 12 is provided, the plurality of electrode tabs 12 are arranged at intervals along the first direction x, that is, the plurality of electrode tabs 12 are arranged at intervals on the first side 16 .

[0034] Furthermore, the tab 12 may be a rectangle, or a trapezoid or other geometric shape, and the user may set it according to the needs, which will not be described in detail here.

[0035] Furthermore, the pole piece 1 also includes a protrusion 13 arranged on the conductive layer 11, the pole piece 1 includes a first end 15, the first end 15 is one end of the pole piece 1 in the first direction x, the pole piece 1 also includes a first side 16 located on one side and a second side located on the other side in the second direction y, the protrusion 13 is arranged on the first side 16 of the first end 15 of the conductive layer 11; the protrusion 13 and the conductive layer 11 are formed integrally, or can be separately arranged. When the protrusion 13 and the conductive layer 11 are separately arranged, the protrusion 13 is fixedly connected to the conductive layer 11, such as by welding, etc. This fixed connection belongs to the prior art, and the user can choose to set it according to needs, which will not be repeated here.

[0036] Furthermore, one or two protrusions 13 can be provided. When two protrusions 13 are provided, the protrusions 13 are located at both ends of the pole piece 1 in the first direction x, and are provided at both ends of the conductive layer 11 in the first direction x and on one side of the second direction y, so that when the pole piece 1 is wound into a winding core, the protrusions 13 can be folded to be attached to the axial end face of the winding core, thereby preventing the pole piece 1 from being folded at the end in the first direction x.

[0037] Furthermore, the protrusion 13 includes a first end face a, and the conductive layer 11 includes a second end face b. The first end face a is flush with the second end face b, so that after the pole piece 1 is wound into a core and the protrusion 13 is folded to be close to the end face of the core, the end of the pole piece 1 in the first direction x can be effectively prevented from being folded, thereby ensuring the structural stability and service life of the battery.

[0038] Furthermore, the protrusion 13 is rectangular. In other embodiments, the protrusion 13 may also be trapezoidal or other shapes. The user may select and set the shape as needed, which will not be described in detail here.

[0039] Furthermore, in the second direction y, the size of the tab 12 is h 1, the size of the protrusion 13 is h 2 , where 0.4≤h 2 / h 1 ≤0.6, preferably, h 2 / h 1 =0.5. The above ratio selection setting can prevent the h of the protrusion 13 from 2 If it is too small, it will affect the effect of preventing the end of the pole piece 1 from folding, and on the other hand, it can prevent the h of the protrusion 13 2 Too large will lead to increased costs and increased space occupancy, which in turn affects the overall energy density of the battery.

[0040] Furthermore, the first direction x is the length direction of the pole piece 1 , and the second direction y is the width direction of the pole piece 1 .

[0041] See also Figure 3 and Figure 4 , the battery cell of the utility model is described.

[0042] See also Figure 3 and Figure 4 As shown, the battery cell includes a wound first pole piece 1 ′, a diaphragm 2 and a second pole piece 1 ″, the first pole piece 1 ′ or the second pole piece 1 ″ is any one of the pole pieces 1 mentioned above, and the protrusion 13 is attached to the end surface of the battery cell 10 .

[0043] Furthermore, the diaphragm 2 is located between the first electrode 1' and the second electrode 1", and is used to insulate the first electrode 1' and the second electrode 1". The first electrode 1' and the second electrode 1" have opposite polarities. For example, when the first electrode 1' is a positive electrode, the second electrode 1" is a negative electrode, or when the first electrode 1' is a negative electrode, the second electrode 1" is a positive electrode, etc. The user can set it according to needs, which will not be elaborated here.

[0044] Furthermore, the separator 2 is generally made of a high-strength, thin-film polyolefin-based porous membrane, or a polypropylene (PP) and polyethylene (PE) microporous separator, a copolymer of propylene and ethylene, a polyethylene homopolymer, and the like.

[0045] Furthermore, the tabs of the first pole piece 1' and the tabs of the second pole piece 1" are arranged on two sides of the battery cell, which are the two sides of the axial direction of the battery cell, so that the positive electrode or the negative electrode can be output from the two sides of the axial direction of the battery cell respectively.

[0046] The utility model also provides a battery (not shown), which includes any one of the above-mentioned battery cells.

[0047] It should be noted that the above preferred implementations are only used to illustrate the principle of the utility model and are not intended to limit the protection scope of the utility model. Without departing from the principle of the utility model, those skilled in the art may adjust the above settings so that the utility model can be applied to more specific application scenarios.

[0048] Of course, the above-mentioned replaceable implementations, as well as the replaceable implementations and the preferred implementations, can be used in a cross-coordinated manner to combine new implementations to suit more specific application scenarios.

[0049] So far, the technical solution of the utility model has been described in conjunction with the preferred embodiments shown in the accompanying drawings, but it is easy for those skilled in the art to understand that the protection scope of the utility model is obviously not limited to these specific embodiments. Without departing from the principle of the utility model, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will fall within the protection scope of the utility model.

Claims

1. A pole piece, characterized in that: The pole piece includes a conductive layer and an active material layer arranged on the conductive layer. The conductive layer is provided with a protrusion on a first side of a first end portion.

2. The pole piece according to claim 1, characterized in that: The conductive layer further includes a plurality of tabs, and the plurality of tabs are spaced apart on the first side.

3. The pole piece according to claim 2, characterized in that: The pole ear is rectangular or trapezoidal.

4. The pole piece according to claim 2, characterized in that: The protrusions are provided with two and are located at two ends of the pole piece.

5. The pole piece according to claim 1, characterized in that: The protrusion is rectangular.

6. The pole piece according to claim 1, characterized in that: The protrusion includes a first end surface, the conductive layer includes a second end surface, and the first end surface is flush with the second end surface.

7. The pole piece according to claim 2, characterized in that: In the second direction, the size of the pole ear is h1, and the size of the protrusion is h2, wherein 0.4≤h2 / h1≤0.

6.

8. A battery cell, characterized in that: The battery cell comprises a wound first pole piece, a diaphragm and a second pole piece, the first pole piece or the second pole piece is the pole piece according to any one of claims 1 to 7, and the protrusion is in contact with the end face of the battery cell.

9. The battery cell according to claim 8, characterized in that: The pole lug of the first pole piece and the pole lug of the second pole piece are arranged on two sides of the battery cell.

10. A battery, characterized in that: The battery comprises the battery cell according to claim 8 or 9.

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