Battery cell structure without bus bar

Abstract

The utility model provides a bus-bar-free battery cell structure which comprises a plurality of integrated positive plates, a plurality of integrated negative plates and a plurality of diaphragms, and the integrated positive plates and the integrated negative plates are arranged in a stacked manner; the diaphragms are arranged on the outermost side of the bus-bar-free battery cell structure and between the integrated positive plate and the integrated negative plate; the integrated positive plate comprises a first positive plate, a second positive plate and at least one positive tab; one end of the positive tab is connected with the first positive plate, and the other end of the positive tab is connected with the second positive plate; and the first positive plate and the second positive plate are symmetrically arranged. The integrated parallel battery cell can be realized, the cost is saved, the assembly efficiency is improved, the overcurrent capability of the battery cell is effectively improved, and the high-rate application of the battery cell is facilitated. Through the structure, heat generated by the battery cell can be effectively reduced, so that the safety performance of the battery cell is improved; meanwhile, the tab folding risk can be avoided, and the potential safety hazard of the product is reduced.

Description

Technical Field

[0001] The utility model belongs to the technical field of batteries, and in particular relates to a busbar-free battery core structure. Background Art

[0002] Lithium battery is a common rechargeable battery, which is widely used in mobile devices and electric vehicles. It has become the focus of my country's energy structure transformation. With the rapid development of lithium battery technology, large capacity, long life, high safety and low cost have become the core keywords of new energy storage. Among them, the square stacking process has stronger adaptability and safety due to its structure, and has the characteristics of multi-stage parallel connection, lower impedance, high-rate and high-current charging and discharging, and the cycle life can be increased by 10%-20%, becoming the mainstream technology in the field of large energy storage and power energy.

[0003] The existing stacking process generally consists of two single cells in parallel. Through the butterfly welding process, the pole ear and the connecting piece of the single cell are first ultrasonically welded, and then the connecting piece is connected to the pole. This method has two connections: the connection between the pole ear and the busbar (connecting piece) and the connection between the busbar (connecting piece) and the pole. The above connection method adds a welding step, has low production efficiency and low yield rate, and the internal resistance of the battery cell is high, which also affects the current carrying capacity of the pole ear. Utility Model Content

[0004] The embodiment of the utility model provides a busbar-free battery cell structure, aiming to solve the problems of the existing square lamination process being complex, low production efficiency, low yield, high battery cell internal resistance, and affecting the current carrying capacity of the tabs.

[0005] To achieve the above-mentioned purpose, the embodiment of the utility model provides a busbar-free battery core structure, comprising a plurality of integrated positive electrode sheets, a plurality of integrated negative electrode sheets and a plurality of separators, wherein the integrated positive electrode sheets and the integrated negative electrode sheets are stacked, and the separators are arranged at the outermost side of the busbar-free battery core structure and between the integrated positive electrode sheets and the integrated negative electrode sheets;

[0006] The integrated positive electrode sheet includes a first positive electrode sheet, a second positive electrode sheet and at least one positive electrode ear; one end of the positive electrode ear is connected to the first positive electrode sheet, and the other end is connected to the second positive electrode sheet; the first positive electrode sheet and the second positive electrode sheet are symmetrically arranged.

[0007] As a preferred embodiment, the first positive electrode sheet, the positive electrode tab and the second positive electrode sheet are integrally formed.

[0008] As a preferred embodiment, the integrated negative electrode sheet includes a first negative electrode sheet, a second negative electrode sheet and at least one negative electrode ear; one end of the negative electrode ear is connected to the first negative electrode sheet, and the other end is connected to the second negative electrode sheet; the first negative electrode sheet and the second negative electrode sheet are symmetrically arranged.

[0009] As a preferred embodiment, the first negative electrode sheet, the negative electrode tab and the second negative electrode sheet are integrally formed.

[0010] As a preferred embodiment, when the integrated positive electrode sheet and the integrated negative electrode sheet are stacked, the first positive electrode sheet and the first negative electrode sheet are stacked, the second positive electrode sheet and the second negative electrode sheet are stacked, and the positive electrode tab and the negative electrode tab are symmetrically arranged.

[0011] As a preferred embodiment, a gap is provided between the positive electrode tab and the negative electrode tab. The number of positive electrode tabs and negative electrode tabs can be set according to actual needs, and is not limited to a single electrode tab, and multiple electrodes can also realize the present application solution.

[0012] As a preferred embodiment, the positive electrode tab is welded to the positive electrode post, and the negative electrode tab is welded to the negative electrode post. In this way, the battery cell structure is directly welded to the cover plate without the need for a connecting sheet, thus reducing the welding process.

[0013] As a preferred embodiment, the first positive electrode sheet and the first negative electrode sheet have the same shape and size; the second positive electrode sheet and the second negative electrode sheet have the same shape and size.

[0014] As a preferred embodiment, the busbar-free battery cell structure is a laminated battery cell structure or a wound battery cell structure.

[0015] The battery cell structure of the present application adopts an integrated positive electrode sheet and an integrated negative electrode sheet, which can realize an integrated parallel battery cell, and the stacking efficiency can be increased by 50%. At the same time, the assembly process can reduce the ultrasonic welding process of the connecting piece and the pole ear, which not only saves the cost of the positive and negative connecting pieces, but also improves the assembly efficiency. In addition, since the connection nodes between the connecting piece and the pole ear are reduced, the current capacity of the battery cell is effectively improved, which is conducive to the high-rate application of the battery cell. Through the structure of the present application, the heat generation of the battery cell can be effectively reduced, thereby improving the safety performance of the battery cell; at the same time, the risk of the pole ear being discounted can be avoided, reducing the potential safety hazards of the product. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying creative work.

[0017] Figure 1 This is a schematic structural diagram of a busbar-free battery cell structure according to an embodiment of the present invention;

[0018] Figure 2 yes Figure 1 Schematic diagram of a partial explosion structure of a busbar-free battery cell structure;

[0019] Figure 3 yes Figure 1 A schematic diagram of the structure of an integrated positive electrode sheet of a busbar-free battery cell structure;

[0020] Figure 4 yes Figure 1 A schematic diagram of the structure of an integrated negative electrode sheet of a busbar-free battery cell structure;

[0021] Figure 5 yes Figure 1 Schematic diagram of the assembly structure of the busbar-free battery cell structure and the cover plate welding. DETAILED DESCRIPTION

[0022] The technical solutions in the embodiments of the present utility model are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present utility model, not all of them. Based on the embodiments of the present utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present utility model.

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

[0024] In this application, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like 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 an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0025] It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it may be directly on the other element or there may be an intermediate element. When an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be an intermediate element at the same time.

[0026] In addition, if there are descriptions involving "first", "second", etc. in the embodiments of the utility model, the descriptions of "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or suggesting their relative importance or implicitly indicating the number of the indicated technical features. 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 the 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 utility model.

[0027] Specifically, Figures 1 to 3 As shown, the embodiment of the utility model provides a busbar-free battery cell structure, comprising several integrated positive electrode sheets 10, several integrated negative electrode sheets 20 and several separators 30, wherein the integrated positive electrode sheets 10 and the integrated negative electrode sheets 20 are stacked, and the separators 30 are arranged at the outermost side of the busbar-free battery cell structure and between the integrated positive electrode sheets 10 and the integrated negative electrode sheets 20;

[0028] The integrated positive electrode sheet 10 includes a first positive electrode sheet 11, a second positive electrode sheet 12 and at least one positive electrode ear 13; one end of the positive electrode ear 13 is connected to the first positive electrode sheet 11, and the other end is connected to the second positive electrode sheet 12; the first positive electrode sheet 11 and the second positive electrode sheet 12 are symmetrically arranged.

[0029] As a preferred embodiment, the first positive electrode sheet 11 , the positive electrode tab 13 and the second positive electrode sheet 12 are integrally formed.

[0030] As a preferred embodiment, Figure 4As shown, the integrated negative electrode sheet 20 includes a first negative electrode sheet 21, a second negative electrode sheet 22 and at least one negative electrode ear 23; one end of the negative electrode ear 23 is connected to the first negative electrode sheet 21, and the other end is connected to the second negative electrode sheet 22; the first negative electrode sheet 21 and the second negative electrode sheet 22 are symmetrically arranged.

[0031] As a preferred embodiment, the first negative electrode sheet 21 , the negative electrode tab 23 and the second negative electrode sheet 22 are integrally formed.

[0032] As a preferred embodiment, when the integrated positive electrode sheet 10 and the integrated negative electrode sheet 20 are stacked, the first positive electrode sheet 11 and the first negative electrode sheet 21 are stacked, the second positive electrode sheet 12 and the second negative electrode sheet 22 are stacked, and the positive electrode ear 13 and the negative electrode ear 23 are symmetrically arranged.

[0033] As a preferred embodiment, a gap is provided between the positive electrode tab 13 and the negative electrode tab 23. The number of the positive electrode tab 13 and the negative electrode tab 23 can be set according to actual needs, and is not limited to a single electrode tab, and multiple electrodes can also realize the present application solution.

[0034] As a preferred embodiment, Figure 5 As shown, the positive electrode tab 13 is welded to the positive electrode post, and the negative electrode tab 23 is welded to the negative electrode post. In this way, the battery cell structure is directly welded to the cover plate without the need for a connecting sheet, thereby reducing the welding process.

[0035] As a preferred embodiment, the first positive electrode sheet 11 and the first negative electrode sheet 21 have the same shape and size; the second positive electrode sheet 12 and the second negative electrode sheet 22 have the same shape and size.

[0036] As a preferred embodiment, the busbar-free battery cell structure is a laminated battery cell structure or a wound battery cell structure.

[0037] Specifically, in the present embodiment, the busbar-free cell structure is a stacked cell structure, and the stacking method adopts a "Z"-shaped stacking process. During the stacking process, the stacking of a single bare cell is completed through the combination stacking method of diaphragm + integrated negative electrode sheet + diaphragm + integrated positive electrode sheet + diaphragm + integrated negative electrode sheet... + integrated negative electrode sheet + diaphragm, thereby completing the production of the entire cell, and the stacking efficiency is increased by 50%. The stacked cells can then be welded to the cover plate.

[0038] It is understandable that, in other embodiments, the busbar-free battery cell structure may also be a wound battery cell structure, which is formed by stacking an integrated positive electrode sheet and an integrated negative electrode sheet and then winding them.

[0039] The battery cell structure of the present application adopts an integrated positive electrode sheet and an integrated negative electrode sheet, which can realize an integrated parallel battery cell, and the stacking efficiency can be increased by 50%. At the same time, the assembly process can reduce the ultrasonic welding process of the connecting piece and the pole ear, which not only saves the cost of the positive and negative connecting pieces, but also improves the assembly efficiency. In addition, since the connection nodes between the connecting piece and the pole ear are reduced, the current capacity of the battery cell is effectively improved, which is conducive to the high-rate application of the battery cell. Through the structure of the present application, the heat generation of the battery cell can be effectively reduced, thereby improving the safety performance of the battery cell; at the same time, the risk of the pole ear being discounted can be avoided, reducing the potential safety hazards of the product.

[0040] In the description of this specification, the description with reference to the terms "an embodiment", "example", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the utility model. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example.

[0041] In addition, it should be understood that although this specification is described according to implementation methods, not every implementation method contains only one independent technical solution. This narrative method of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation methods that can be understood by those skilled in the art.

[0042] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A busbar-free battery cell structure, characterized in that: It comprises several integrated positive electrode sheets, several integrated negative electrode sheets and several separators, wherein the integrated positive electrode sheets and the integrated negative electrode sheets are stacked, and the separators are arranged at the outermost side of the busbar-free battery structure and between the integrated positive electrode sheets and the integrated negative electrode sheets; The integrated positive electrode sheet includes a first positive electrode sheet, a second positive electrode sheet and at least one positive electrode ear; one end of the positive electrode ear is connected to the first positive electrode sheet, and the other end is connected to the second positive electrode sheet; the first positive electrode sheet and the second positive electrode sheet are symmetrically arranged.

2. The busbar-free battery cell structure according to claim 1, characterized in that: The first positive electrode sheet, the positive electrode tab and the second positive electrode sheet are integrally formed.

3. The busbar-free battery cell structure according to claim 1, characterized in that: The integrated negative electrode sheet comprises a first negative electrode sheet, a second negative electrode sheet and at least one negative electrode ear; one end of the negative electrode ear is connected to the first negative electrode sheet, and the other end is connected to the second negative electrode sheet; the first negative electrode sheet and the second negative electrode sheet are symmetrically arranged.

4. The busbar-free battery cell structure according to claim 3, characterized in that: The first negative electrode sheet, the negative electrode ear and the second negative electrode sheet are integrally formed.

5. The busbar-free battery cell structure according to claim 3, characterized in that: When the integrated positive electrode sheet and the integrated negative electrode sheet are stacked, the first positive electrode sheet and the first negative electrode sheet are stacked, the second positive electrode sheet and the second negative electrode sheet are stacked, and the positive electrode tab and the negative electrode tab are symmetrically arranged.

6. The busbar-free battery cell structure according to claim 5, characterized in that: A gap is provided between the positive electrode tab and the negative electrode tab.

7. The busbar-free battery cell structure according to claim 6, characterized in that: The positive electrode ear is connected to the positive electrode post by welding, and the negative electrode ear is connected to the negative electrode post by welding.

8. The busbar-free battery cell structure according to claim 5, characterized in that: The first positive electrode sheet and the first negative electrode sheet have the same shape and size; the second positive electrode sheet and the second negative electrode sheet have the same shape and size.

9. The busbar-free battery cell structure according to claim 1, characterized in that: The busbar-free battery cell structure is a laminated battery cell structure or a wound battery cell structure.

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