Battery cell without SA structure

Abstract

The utility model discloses a battery cell without an SA structure, and relates to the technical field of lithium ion batteries. Comprising a negative plate and a positive plate, the negative plate and the positive plate are stacked, a diaphragm is connected between the negative plate and the positive plate, the length of the diaphragm is equal to that of the positive plate and smaller than that of the negative plate, insulators are arranged at least at two ends of one side, close to the diaphragm, of the positive plate, and the insulators extend from the end part of the positive plate to the center direction. According to the battery cell without the SA structure provided by the utility model, the energy density of the battery cell is improved and the space for temporarily storing electrolyte is expanded by reducing SA to 0, and the insulators are arranged at the two ends of the positive plate, so that when thermal runaway occurs, short circuit caused by contact between the positive plate and the negative plate is avoided by compounding the insulators and the diaphragms, and the safety of the battery cell is ensured; and the performance of the battery cell is improved.

Description

TECHNICAL FIELD

[0001] The utility model relates to the technical field of lithium ion battery, more particularly to a kind of battery cell without SA structure. BACKGROUND

[0002] The structure design of existing lithium ion battery cell generally designs overhang, i.e. the overhanging part of positive electrode, negative electrode or diaphragm in edge area, including: diaphragm to negative electrode tab overhang (referred to as SA) refers to the part of diaphragm edge overhanging negative active material, diaphragm to positive electrode tab overhang (referred to as SC) refers to the part of diaphragm edge overhanging positive active material, negative electrode tab to positive electrode tab overhang (referred to as AC) refers to the part of negative active material edge overhanging positive active material. Generally, the design of SA is considered from the aspect of short circuit safety, and the larger the excess area is, the better; but the larger the excess area design is, the lower the energy density of the battery cell is, and it will affect the performance of the battery. Therefore, how to provide a battery cell that can guarantee safety and energy density is a problem that technicians in the field need to solve. SUMMARY

[0003] Therefore, the utility model provides a kind of battery cell without SA structure, which can guarantee the safety of battery cell while guaranteeing the energy density of battery cell. To achieve the above purpose, the utility model adopts the following technical solutions:

[0004] The utility model provides a kind of battery cell without SA structure, comprising:

[0005] Negative tab and positive tab, the negative tab and positive tab are stacked, a diaphragm is arranged between the negative tab and positive tab, the length of the diaphragm is equal to the length of the positive tab and less than the length of the negative tab, the positive tab is provided with an insulator at least at both ends of the side close to the diaphragm, and the insulator extends from the end of the positive tab to the center direction.

[0006] Further, the negative tab includes a negative foil and two layers of negative paste coating, the two layers of negative paste coating are arranged on both sides of the negative foil, and one layer of diaphragm is arranged on the side of the negative paste coating away from the negative foil.

[0007] Further, the positive tab includes a positive foil and two layers of positive paste coating, the two layers of positive paste coating are arranged on both sides of the positive foil, the side of the positive paste coating away from the positive foil is in contact with the diaphragm, the insulator is arranged at both ends of the positive paste coating, and the sum of the length of the positive paste coating and the length of the insulator is equal to the length of the positive foil.

[0008] Further, the insulator comprises a ceramic layer in contact with the positive electrode foil and a hot melt adhesive layer disposed on a side of the ceramic layer away from the positive electrode foil.

[0009] Further, the insulator is a ceramic hot melt mixed layer formed by uniformly mixing ceramic and hot melt adhesive.

[0010] Via the technical solution described above, compared with the prior art, the utility model discloses provide a kind of electric core without SA structure, by reducing SA, make SA 0, improve the energy density of electric core, expand the space of temporary electrolyte simultaneously, insulator is set in the both ends of positive sheet, when thermal runaway occurs, insulator and diaphragm are compounded together, avoid diaphragm shrinkage by insulator, to prevent positive sheet and negative sheet continue to contact and cause short circuit again, ensure the safety of electric core, improve the performance of electric core. BRIEF DESCRIPTION OF DRAWINGS

[0011] In order to more clearly illustrate the technical scheme in the embodiments of the present application or the prior art, the drawings needed to be used in the following embodiment or prior art description will be briefly introduced. Obviously, the drawings in the following description are only embodiments of the present application, and for those skilled in the art, other drawings can be obtained without creative labor on the basis of the provided drawings.

[0012] Figure 1 The structure diagram of the electric core without SA structure provided by the present application is shown.

[0013] In the figure: 1, diaphragm; 2, negative electrode paste coating; 3, negative electrode foil; 4, insulator; 5, positive electrode paste coating; 6, positive electrode foil. DETAILED DESCRIPTION

[0014] The technical scheme in the embodiments of the present application will be described clearly and completely in the following with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application.

[0015] Referring to Figure 1 The embodiments of the present application disclose an electric core without SA structure, comprising:

[0016] The negative sheet and the positive sheet are laminated, and the diaphragm 1 is arranged between the negative sheet and the positive sheet. The length of the diaphragm 1 is equal to the length of the positive sheet and less than the length of the negative sheet. The positive sheet is provided with the insulator 4 at least on both ends of the side close to the diaphragm 1, and the insulator 4 extends from the end of the positive sheet to the center direction.

[0017] In some embodiments, the insulator 4 is arranged between the two ends of the positive plate close to one side of the diaphragm 1.

[0018] By reducing the size of the diaphragm 1, reducing the SA, making the SA 0, the energy density of the battery cell is improved, and the space for temporarily storing electrolyte is expanded, which is beneficial to improve the cycle and storage performance of the battery. When thermal runaway occurs, the diaphragm 1 and the insulator 4 are combined together, which prevents the diaphragm 1 from shrinking and prevents the positive plate from contacting the negative plate, thereby preventing the short circuit phenomenon from occurring again and ensuring the safety of the battery cell.

[0019] In some embodiments, the negative plate includes a negative foil 3 and two layers of negative slurry coating 2 arranged on both sides of the negative foil 3, and a diaphragm 1 is arranged on the side of the negative slurry coating 2 away from the negative foil 3.

[0020] By arranging the negative slurry coating on both sides of the negative foil 3, the performance of the battery cell is improved.

[0021] In some embodiments, the positive plate includes a positive foil 6 and two layers of positive slurry coating 5 arranged on both sides of the positive foil 6, the positive slurry coating 5 contacts the diaphragm 1 on the side away from the positive foil 6, and the insulator 4 is arranged at both ends of the positive slurry coating 5. The sum of the lengths of the positive slurry coating 5 and the insulator 4 is equal to the length of the positive foil 6.

[0022] By arranging the positive slurry coating on both sides of the positive foil 6, the risk of heat generation and thermal runaway is reduced, the strength of the battery cell is improved, the risk of damage during use is reduced, and the performance of the battery cell is optimized.

[0023] In some embodiments, the insulator 4 includes a ceramic layer and a hot melt adhesive layer, the ceramic layer contacts the positive foil 6, and the hot melt adhesive layer is arranged on the side of the ceramic layer away from the positive foil 6.

[0024] In some embodiments, the ceramic layer material uses AT9, and the hot melt adhesive layer material uses PVDF.

[0025] In some embodiments, the insulator 4 is a ceramic hot melt mixed layer formed by uniformly mixing ceramic and hot melt adhesive, and the ceramic hot melt mixed layer is arranged at both ends of the positive slurry coating 5.

[0026] The length of the insulator 4 is less than the length of the positive plate. When thermal runaway occurs, the diaphragm 1 will be combined with the insulator due to the presence of the insulator, which avoids the diaphragm 1 from shrinking and causing further contact and short circuit between the positive and negative plates.

[0027] The various embodiments described in this specification are presented by way of example, and each embodiment is presented for the purpose of conveying the novelty and inventive aspects of the present patent application. Each embodiment is presented in a progressive and explanatory manner, and each embodiment highlights differences from other embodiments. The same or similar parts and / or functions between embodiments are to be understood as mutual references among the embodiments.

[0028] The above description of disclosed embodiments enables one of ordinary skill in the art to make and use the patent application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein can be applied to other embodiments without departing from the spirit or scope of the patent application. Thus, the present patent application is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A cell with no SA structure, characterized in that, The application relates to a battery, comprising: a negative electrode sheet and a positive electrode sheet, the negative electrode sheet and the positive electrode sheet being arranged in a stack, a diaphragm being arranged between the negative electrode sheet and the positive electrode sheet, the diaphragm being equal in length to the positive electrode sheet and shorter in length than the negative electrode sheet, and the positive electrode sheet being provided with an insulator at least on two ends of a side close to the diaphragm, the insulator extending from the end of the positive electrode sheet to the center.

2. The cell without SA structure of claim 1, wherein, The negative electrode sheet comprises a negative electrode foil and two layers of negative electrode paste coating, the two layers of negative electrode paste coating being arranged on two sides of the negative electrode foil, and a layer of the diaphragm being arranged on a side of the negative electrode paste coating away from the negative electrode foil.

3. The cell without SA structure of claim 1, wherein, The positive electrode sheet comprises a positive electrode foil and two layers of positive electrode paste coating, the two layers of positive electrode paste coating being arranged on two sides of the positive electrode foil, the positive electrode paste coating being in contact with the diaphragm on a side away from the positive electrode foil, and the insulator being arranged at two ends of the positive electrode paste coating, the sum of the lengths of the positive electrode paste coating and the insulator being equal to the length of the positive electrode foil.

4. The cell without SA structure of claim 3, wherein, The insulator comprises a ceramic layer and a hot melt adhesive layer, the ceramic layer being in contact with the positive electrode foil, and the hot melt adhesive layer being arranged on a side of the ceramic layer away from the positive electrode foil.

5. The cell without SA structure of claim 3, wherein, The insulator is a ceramic hot melt mixed layer formed by uniformly mixing ceramic and hot melt adhesive.

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