Battery cell

Abstract

The utility model relates to a battery monomer which comprises an aluminum plastic film, an electrode assembly and electrolyte, the aluminum plastic film is used for containing the electrode assembly and the electrolyte, the electrode assembly is composed of a positive plate, a negative plate and diaphragms, the positive plate and the negative plate are sequentially stacked, and the diaphragms are arranged between the adjacent positive plate and negative plate. The electrode assembly is provided with a positive tab and a negative tab, the size of the diaphragm is smaller than that of the aluminum plastic film, and the corners of the diaphragm are cut into inclined planes; the electrode assembly is arranged in an inner cavity of the aluminum-plastic film, the aluminum-plastic film surrounds the positive plate, the negative plate and the diaphragm, and the electrolyte is arranged in the aluminum-plastic film; and the positive tab and the negative tab respectively extend out of the aluminum plastic film. The space layout of the electrodes and the diaphragms is effectively optimized, so that all components in the battery monomer can be arranged more tightly and neatly, and the internal structure mismatching caused by excess diaphragms is reduced.

Description

Technical Field

[0001] The utility model relates to a battery monomer. Background Art

[0002] In the field of battery technology, especially in large-scale energy storage systems, sodium-ion batteries have gradually attracted attention due to their abundant resources and low cost. With the advancement of technology, the capacity and power requirements of sodium-ion battery cells are constantly increasing. In order to reduce the number of parallel batteries in combination, improve system efficiency and reduce costs, the design and manufacturing process of battery cells faces a variety of technical challenges.

[0003] At present, there are three main types of sodium-ion batteries: cylindrical, square aluminum shell, and aluminum-plastic film soft package. Among them, semi-solid and all-solid-state sodium-ion batteries usually adopt aluminum-plastic film soft package. During the manufacturing process of this battery, the electrode sheets and isolation membranes are assembled by stacking them back and forth in a "Z-type" manner. However, this stacking method will produce excess isolation membrane at the four corners of the isolation membrane of the bare battery cell at the oblique angles relative to the pole piece, which not only affects the shelling process of the bare battery cell, but also may squeeze the pole piece, causing wrinkles on the appearance of the battery cell, thereby affecting the overall performance and life of the battery. Utility Model Content

[0004] The utility model aims to provide a battery cell which reduces the problems of space interference and pole piece extrusion, thereby simplifying the process of core shell insertion, and reducing the difficulty of molding and the frequency of appearance wrinkles.

[0005] The purpose of the utility model is achieved in this way:

[0006] A battery cell, comprising an aluminum-plastic film, an electrode assembly and an electrolyte, wherein the aluminum-plastic film is used to contain the electrode assembly and the electrolyte, wherein the electrode assembly is composed of a positive electrode sheet, a negative electrode sheet and a separator, wherein the positive electrode sheet and the negative electrode sheet are stacked in sequence, and the separator is disposed between adjacent positive electrode sheets and negative electrode sheets, wherein the electrode assembly is provided with a positive electrode ear and a negative electrode ear, wherein the size of the separator is smaller than the size of the aluminum-plastic film, and the edges and corners of the separator are cut into bevels;

[0007] The electrode assembly is placed in the inner cavity of the aluminum-plastic film, the aluminum-plastic film surrounds the positive electrode sheet, the negative electrode sheet and the separator, and the electrolyte is arranged in the aluminum-plastic film;

[0008] The positive electrode ear and the negative electrode ear extend out of the aluminum-plastic film respectively.

[0009] Solve the spatial interference problem: By beveling the corners of the diaphragm, the spatial interference caused by excess diaphragm material in the electrode stack is reduced. This design effectively optimizes the spatial layout of the electrodes and diaphragms, allowing the components inside the battery cell to be arranged more closely and neatly, reducing the internal structure mismatch caused by excess diaphragms.

[0010] Reduce pole piece extrusion: In the traditional battery manufacturing process, the mismatch between the diaphragm and the pole piece may cause the pole piece to be extruded during the assembly process, affecting the battery performance. The utility model adjusts the size and shape of the diaphragm to ensure the perfect alignment of the pole piece and the diaphragm, thereby effectively reducing the extrusion of the pole piece and improving the structural stability and performance reliability of the battery cell.

[0011] Improve the efficiency of bare cell pitting: Since the corners of the diaphragm are cut into bevels, the battery assembly process is greatly simplified, especially in the shelling operation of bare cells, which reduces the difficulty of operation and speeds up production. This design makes the production of large-capacity batteries more efficient, especially for large cells above 500Ah, the efficiency improvement is particularly significant.

[0012] Improved cell appearance: The optimized diaphragm design reduces the wrinkle problem that may be caused by improper stacking of pole pieces and diaphragms during battery packaging, thereby improving the appearance quality of the battery cell.

[0013] Improve production efficiency and reduce costs: The design of the utility model simplifies the battery assembly process, reduces errors and scrap rates in the production process, and improves overall production efficiency. At the same time, due to reduced material waste and reduced maintenance costs, the overall production cost is effectively controlled.

[0014] In summary, the design of the battery cell of the utility model not only optimizes the internal structure of the battery and improves the battery performance and reliability, but also increases the production efficiency and cost-effectiveness by simplifying the production process, providing important technical support for the application of sodium-ion batteries in the field of large-scale energy storage.

[0015] The purpose of the utility model can also be solved by the following technical measures:

[0016] Furthermore, the corners of the diaphragm are cut into bevels, and the angle of the bevel is 45°.

[0017] Furthermore, the size of the negative electrode sheet is larger than that of the positive electrode sheet.

[0018] Optimization of negative electrode sheet size: Ensuring that the negative electrode sheet is larger than the positive electrode sheet is another key design of the utility model. This design ensures that during the formation, capacity measurement and cycle stages of the battery, there are sufficient negative electrode locations for the sodium ions or lithium ions from the positive electrode to be embedded. This not only helps to achieve more efficient ion exchange, but also significantly reduces the generation of sodium or lithium dendrites caused by the boundary dislocation effect.

[0019] Furthermore, the corners of the positive electrode sheet are cut into bevels. The corners of the positive electrode sheet are cut into the same shape as the corners of the diaphragm, reducing the spatial interference caused by excess diaphragm material in the electrode stack. This design effectively optimizes the spatial layout of the electrode and the diaphragm, allowing the components inside the battery cell to be arranged more closely and neatly, reducing the internal structure mismatch caused by excess diaphragm.

[0020] Furthermore, the corners of the negative electrode sheet are cut into bevels. The corners of the negative electrode sheet are cut into the same shape as the corners of the diaphragm, reducing the spatial interference caused by excess diaphragm material in the electrode stack. This design effectively optimizes the spatial layout of the electrode and the diaphragm, allowing the components inside the battery cell to be arranged more closely and neatly, reducing the internal structure mismatch caused by excess diaphragm.

[0021] Furthermore, the electrolyte includes sodium hexafluorophosphate and an organic solvent.

[0022] Furthermore, the number of the positive electrode sheet is one less than the number of the negative electrode sheet.

[0023] Reduced manufacturing costs: Reducing one positive electrode sheet can reduce the manufacturing cost of the battery. Positive electrodes usually contain rare metals or high-cost materials, while negative electrodes usually use more common materials. Therefore, reducing one positive electrode sheet can save material costs and reduce the manufacturing cost of the battery.

[0024] Improve energy efficiency: Optimizing the reaction balance between the positive and negative electrodes can improve the energy efficiency of the battery. One less positive electrode sheet than the negative electrode sheet may lead to a more appropriate positive and negative electrode reaction ratio, thereby improving the energy conversion efficiency of the battery and extending the battery life.

[0025] Furthermore, the separator is arranged outside the outermost negative electrode sheet.

[0026] Enhanced battery safety: Placing the separator outside the outermost negative electrode sheet can effectively isolate the positive and negative electrodes of the battery, reducing direct contact between the positive and negative electrodes and the possible short circuit risk. This can reduce the possibility of battery failure during use and improve battery safety.

[0027] Furthermore, the diaphragm is a single piece.

[0028] The beneficial effects of the utility model are as follows:

[0029] The utility model reduces the spatial interference caused by excess diaphragm material in the electrode stack by bevel cutting the diaphragm corners. This design effectively optimizes the spatial layout of the electrodes and diaphragms, allowing the components inside the battery cell to be arranged more closely and neatly, reducing the internal structure mismatch caused by excess diaphragms.

[0030] In the traditional battery manufacturing process, the mismatch between the diaphragm and the pole piece may cause the pole piece to be squeezed during the assembly process, affecting the battery performance. The utility model adjusts the size and shape of the diaphragm to ensure the perfect alignment of the pole piece and the diaphragm, thereby effectively reducing the squeezing of the pole piece and improving the structural stability and performance reliability of the battery cell.

[0031] In the utility model, since the corners of the diaphragm are cut into bevels, the battery assembly process is greatly simplified, especially in the shelling operation of the bare battery core, the operation difficulty is reduced and the production speed is accelerated.

[0032] The utility model reduces the wrinkle problem that may be caused by improper superposition of pole pieces and diaphragms during battery packaging, thereby improving the appearance quality of the battery core. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 Schematic diagram of a positive electrode sheet in the prior art.

[0034] Figure 2 Schematic diagram of a negative electrode sheet in the prior art.

[0035] Figure 3 A schematic diagram of an electrode assembly according to the prior art.

[0036] Figure 4 A schematic diagram of a diaphragm according to the prior art.

[0037] Figure 5 The schematic diagram of the prior art is that the diaphragm is loaded with an aluminum-plastic film.

[0038] Figure 6 It is a schematic diagram of the positive electrode sheet of the utility model.

[0039] Figure 7 It is a schematic diagram of the negative electrode sheet of the present invention.

[0040] Figure 8 It is a schematic diagram of the electrode assembly of the present invention.

[0041] Fig. 9 It is a schematic diagram of the diaphragm of the present utility model.

[0042] Fig.10 The schematic diagram is a diagram of the diaphragm of the utility model being loaded with the aluminum-plastic film.

[0043] Fig.11 Schematic diagram of a battery cell.

[0044] Fig.12 Schematic diagram of the electrode assembly.

[0045] Fig.13 Schematic diagram of the combination of positive electrode sheet, negative electrode sheet and separator. DETAILED DESCRIPTION

[0046] The utility model is further described below in conjunction with the accompanying drawings and embodiments:

[0047] Example, combined with Figures 6 to 13 As shown, a battery cell comprises an aluminum-plastic film 4, an electrode assembly 5 and an electrolyte, wherein the aluminum-plastic film 4 is used to contain the electrode assembly 5 and the electrolyte, wherein the electrode assembly 5 is composed of a positive electrode sheet 1, a negative electrode sheet 2 and a separator 3, wherein the positive electrode sheet 1 and the negative electrode sheet 2 are stacked in sequence, and the separator 3 is disposed between adjacent positive electrode sheets 1 and negative electrode sheets 2, wherein the electrode assembly 5 is provided with a positive electrode ear 11 and a negative electrode ear 12, wherein the size of the separator 3 is smaller than the size of the aluminum-plastic film 4, and the corners of the separator 3 are cut into a bevel 31;

[0048] The electrode assembly 5 is placed in the inner cavity of the aluminum-plastic film 4, the aluminum-plastic film 4 surrounds the positive electrode sheet 1, the negative electrode sheet 2 and the separator 3, and the electrolyte is arranged in the aluminum-plastic film 4;

[0049] The positive electrode tab 11 and the negative electrode tab 12 extend out of the aluminum-plastic film 4 respectively.

[0050] Furthermore, the corners of the diaphragm are cut into a slope 31, and the angle of the slope 31 is 45°.

[0051] Furthermore, the size of the negative electrode sheet 2 is larger than that of the positive electrode sheet 1 .

[0052] Furthermore, the corners of the positive electrode sheet are cut into bevels.

[0053] Furthermore, the corners of the negative electrode sheet are cut into bevels.

[0054] Furthermore, the electrolyte includes sodium hexafluorophosphate and an organic solvent.

[0055] Furthermore, the number of the positive electrode sheet 1 is less than that of the negative electrode sheet 2 .

[0056] Furthermore, the separator 3 is arranged outside the outermost negative electrode sheet 2 .

[0057] Furthermore, the diaphragm 3 is a single piece.

[0058] Made into BT120888699, capacity 600Ah, top head length 1200mm, of which the main part is 888mm, the airbag part is 318mm, and the width is 10mm.

[0059] The size of the positive electrode sheet 1 is: 876mm (W) * 663mm (L) and the four corners are cut into bevels.

[0060] The size of the negative electrode sheet 2 is: 880mm (W) * 667mm (L), and the four corners are cut into bevels.

[0061] The size of the diaphragm 3 is 886*674 mm, and the corners of the diaphragm 3 are cut into bevels 31.

[0062] The corners of the diaphragm are made of right angles and bevels, and the tests are shown in the following table.

[0063] Case This utility model patented product Existing technology (such as Figures 1 to 5 ) Aluminum plastic film 4 damage rate 0.0012％ 0.005％ Corner wrinkle rate 0.003％ 0.010％ Repair rate 3.5PPM 0.01％

Claims

1. A battery cell, comprising an aluminum-plastic film (4), an electrode assembly (5) and an electrolyte, wherein the aluminum-plastic film (4) is used to contain the electrode assembly (5) and the electrolyte, the electrode assembly (5) is composed of a positive electrode sheet (1), a negative electrode sheet (2) and a separator (3), the positive electrode sheet (1) and the negative electrode sheet (2) are stacked in sequence, and the separator (3) is provided between adjacent positive electrode sheets (1) and negative electrode sheets (2), the electrode assembly (5) is provided with a positive electrode ear (11) and a negative electrode ear (12), characterized in that: The size of the diaphragm (3) is smaller than the size of the aluminum-plastic film (4), and the corners of the diaphragm (3) are cut into inclined surfaces (31); The electrode assembly (5) is placed in the inner cavity of the aluminum-plastic film (4), the aluminum-plastic film (4) surrounds the positive electrode sheet (1), the negative electrode sheet (2) and the separator (3), and the electrolyte is arranged in the aluminum-plastic film (4); The positive electrode ear (11) and the negative electrode ear (12) extend out of the aluminum-plastic film (4) respectively.

2. The battery cell according to claim 1, characterized in that: The size of the negative electrode sheet (2) is larger than that of the positive electrode sheet (1).

3. The battery cell according to claim 1, characterized in that: The corners of the diaphragm (3) are cut into bevels (31), and the angle of the bevels (31) is 45°.

4. The battery cell according to claim 1, characterized in that: The corners of the positive electrode sheet (1) are cut into inclined surfaces (31).

5. The battery cell according to claim 1, characterized in that: The corners of the negative electrode sheet (2) are cut into inclined surfaces (31).

6. The battery cell according to claim 1, characterized in that: The electrolyte includes sodium hexafluorophosphate and an organic solvent.

7. The battery cell according to claim 1, characterized in that: The number of the positive electrode sheet (1) is one less than that of the negative electrode sheet (2).

8. The battery cell according to claim 1, characterized in that: The separator (3) is arranged outside the outermost negative electrode sheet (2).

9. The battery cell according to claim 1, characterized in that: The diaphragm (3) is a single piece.

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