Battery cell

Abstract

The utility model relates to a battery monomer which comprises a shell, an electrode assembly and electrolyte, the shell is used for containing the electrode assembly and the electrolyte, the electrode assembly is composed of a positive plate, a negative plate and a diaphragm, the electrode assembly is provided with a positive tab and a negative tab, the positive tab and the negative tab respectively extend out of the shell, and the shell is provided with a positive electrode and a negative electrode. The positive tab and the negative tab are oppositely arranged; the battery monomers mainly work by moving metal ions between the positive plate and the negative plate, at least two hot melt sealants are arranged between the positive tab and the shell from top to bottom, and a gap is formed between every two adjacent hot melt sealants; the positive tab and the shell are bonded through a hot melt sealant; at least two hot melt sealants are arranged between the negative tab and the shell from top to bottom, so that the application of the sodium ion battery in the field of large-scale energy storage is facilitated.

Description

Technical Field

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

[0002] As the application of sodium-ion batteries in large-scale energy storage continues to increase, the demand for single-cell capacity is also gradually increasing to meet the needs of large energy storage, high safety and high efficiency. The positive and negative current collectors and tabs of sodium-ion batteries are made of aluminum metal. Traditional soft-pack sodium batteries usually use aluminum strips and a CPP glue to form a tab structure. Generally, the width of the aluminum strip is 3-5mm and the thickness is 0.1-0.5mm. For small-sized batteries, such as 3C products or passenger car products, this aluminum strip tab structure does not have manufacturing quality and stability problems.

[0003] However, in large-sized batteries with a top seal length of 1000-2000mm, the traditional method uses a piece of hot-melt sealant for bonding to fix the connection between the positive and negative tabs and the shell. Since the parallelism is difficult to control stably for a long time, problems caused by poor top seal quality often occur during the production process. These problems are mainly manifested as incomplete or loose packaging, which leads to battery leakage and swelling. Utility Model Content

[0004] The utility model aims to provide a battery monomer with improved packaging quality and stability.

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

[0006] A battery cell comprises a shell, an electrode assembly and an electrolyte, wherein the shell is used to contain the electrode assembly and the electrolyte.

[0007] The electrode assembly is composed of a positive electrode sheet, a negative electrode sheet and a separator, and the electrode assembly is provided with a positive electrode ear and a negative electrode ear, the positive electrode ear and the negative electrode ear are respectively extended out of the shell, and the positive electrode ear and the negative electrode ear are arranged opposite to each other;

[0008] The battery cell mainly works by the movement of metal ions between the positive electrode sheet and the negative electrode sheet. At least two sheets of hot-melt sealant are arranged between the positive electrode ear and the shell. The multiple sheets of hot-melt sealant are arranged from top to bottom, and a gap is formed between two adjacent sheets of hot-melt sealant. The positive electrode ear and the shell are bonded by the hot-melt sealant.

[0009] At least two sheets of hot melt sealant are arranged between the negative electrode ear and the shell, and the multiple sheets of hot melt sealant are arranged from top to bottom, and a gap is formed between two adjacent sheets of hot melt sealant. The negative electrode ear and the shell are bonded by the hot melt sealant.

[0010] Good sealing performance: Hot melt sealant melts and is applied at high temperature, then solidifies at room temperature to form a strong sealing layer, which can effectively prevent electrolyte leakage and external impurities from entering the battery, ensuring the sealing performance of the battery.

[0011] Improve mechanical strength: Hot melt sealant has good mechanical strength and adhesion, which can firmly fix the connection between the positive and negative ears and the shell, preventing loosening or falling off during transportation and use, thereby improving the durability and safety of the battery.

[0012] Simplified production process: The coating and curing process of hot melt sealant is relatively simple, which can be coordinated with the production process of the battery, improving production efficiency. Compared with other sealing methods, the production process of hot melt sealant is more flexible and controllable.

[0013] Wide adaptability: Hot melt sealant can be applied to batteries of various sizes and shapes, and can meet the requirements of different battery packaging structures. At the same time, it can also be applied to shells and tabs of different materials, and has strong adaptability.

[0014] Improve packaging quality and stability: By dividing a traditional hot-melt sealant into two or more pieces for bonding, the connection between the positive and negative tabs and the shell can be more effectively fixed, ensuring the quality and reliability of the packaging. This design can solve the problem of loose sealing and over-sealing short circuit in traditional tab structures, improve the packaging quality and stability of the battery, and reduce the risk of battery leakage and swelling.

[0015] Enhanced parallelism control capability: Due to the setting method of hot melt sealant, the parallelism between the positive and negative tabs and the shell can be better controlled. This design can effectively improve the parallelism control capability during the manufacturing process and reduce the poor packaging quality caused by parallelism problems. Especially for large-size batteries, parallelism control is particularly important, and this design can effectively improve the manufacturing quality of the battery.

[0016] Improve safety: Due to the excellent bonding properties of hot-melt sealant, it can effectively prevent the tabs from detaching from the battery shell during use, thereby reducing the occurrence of safety problems such as battery short circuit and leakage, and improving the safety of the battery.

[0017] Solving the packaging problem of large-capacity sodium-ion solid-state batteries: Sodium-ion batteries are usually large in size, especially in large-capacity batteries. This innovative design can effectively solve the quality stability problem in the packaging process of large-capacity sodium-ion solid-state batteries, especially the production quality problem of top seal, and improve the manufacturing reliability and stability of the battery.

[0018] In summary, this innovative design has significant beneficial effects in improving packaging quality and stability, enhancing parallelism control capabilities, and improving safety, which will help promote the application of sodium-ion batteries in large-scale energy storage fields.

[0019] The purpose of the utility model can also be solved by the following technical measures:

[0020] Furthermore, the length of the hot melt sealant is shorter than the length of the shell.

[0021] Furthermore, the width of the hot melt sealant ranges from 5 mm to 8 mm.

[0022] Furthermore, the shell is an aluminum-plastic film, the positive electrode sheets and the negative electrode sheets are stacked in sequence, and the separator is arranged between adjacent positive electrode sheets and negative electrode sheets;

[0023] The positive electrode ear and the negative electrode ear are arranged opposite to each other and are both exposed from the diaphragm;

[0024] 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;

[0025] The electrolyte includes sodium hexafluorophosphate and an organic solvent.

[0026] Enhanced safety: The introduction of aluminum-plastic film can provide an additional physical protection layer, effectively isolate the electrode assembly and electrolyte, reduce the impact of the external environment on the battery, reduce the risk of short circuit or external damage to the battery, and thus improve the safety of the battery.

[0027] Improve stability: The aluminum-plastic film can protect the electrode assembly and electrolyte, reduce the instability factors inside the battery caused by changes in the external environment, and help improve the stability and long-term performance of the battery.

[0028] Improve electrolyte distribution: The electrolyte is set inside the aluminum-plastic film, which can cover the positive electrode sheet, negative electrode sheet and separator more evenly, which helps to improve the distribution and uniformity of the electrolyte and improve the electrochemical performance and cycle stability of the battery.

[0029] Increase the energy density of the battery: The design of wrapping the electrode assembly and electrolyte with aluminum-plastic film can effectively improve the energy density of the battery. The aluminum-plastic film has a light weight and high mechanical strength, which can reduce the weight of the battery and thus increase the energy density of the battery.

[0030] Optimize battery structure: The positive and negative electrodes are arranged opposite to each other and exposed from the diaphragm, making it easier to connect the electrode assembly to the external circuit, thus improving the assembly efficiency and compactness of the battery.

[0031] In summary, the introduction of the aluminum-plastic film design not only improves the safety and stability of the battery, but also helps to optimize the electrolyte distribution, increase the energy density and optimize the battery structure. It is an innovative design with multiple advantages.

[0032] Furthermore, the number of the positive electrode sheet is one less than that of the negative electrode sheet.

[0033] 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.

[0034] 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.

[0035] Furthermore, the separator is arranged outside the outermost negative electrode sheet.

[0036] 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.

[0037] Furthermore, the diaphragm is a single piece.

[0038] The beneficial effects of the utility model are as follows:

[0039] The utility model can more effectively fix the connection between the positive and negative tabs and the shell by dividing a traditional hot melt sealant into two or more pieces for bonding, thereby ensuring the quality and reliability of the package. This design can solve the problem that the traditional tab structure is prone to loose sealing and over-sealing short circuit, improve the packaging quality and stability of the battery, and reduce the risk of battery leakage and swelling.

[0040] The utility model can better control the parallelism between the positive and negative tabs and the shell due to the setting method of the hot melt sealant. This design can effectively improve the parallelism control ability in the manufacturing process and reduce the situation of poor packaging quality caused by parallelism problems. Especially for large-sized batteries, the control of parallelism is particularly important, and this design can effectively improve the manufacturing quality of the battery. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 A schematic diagram of a battery cell.

[0042] Figure 2Schematic diagram of a battery cell (excluding the electrode assembly).

[0043] Figure 3 This is the left side view of the battery cell (excluding the electrode assembly).

[0044] Figure 4 A cross-sectional view of a battery cell (excluding the electrode assembly).

[0045] Figure 5 for Figure 4 Schematic diagram of part A.

[0046] Figure 6 for Figure 4 Schematic diagram of part B.

[0047] Figure 7 Schematic diagram of a battery cell (excluding the shell).

[0048] Figure 8 Schematic diagram of the electrode assembly of a battery cell. DETAILED DESCRIPTION

[0049] The utility model is further described below in conjunction with the accompanying drawings and embodiments:

[0050] Example, combined with Figures 1 to 8 As shown, a battery cell comprises a shell, an electrode assembly 7 and an electrolyte, wherein the shell is used to contain the electrode assembly 7 and the electrolyte.

[0051] The electrode assembly 7 is composed of a positive electrode sheet 1, a negative electrode sheet 2 and a separator 3. The electrode assembly 7 is provided with a positive electrode ear 11 and a negative electrode ear 12. The positive electrode ear 11 and the negative electrode ear 12 extend out of the housing respectively, and the positive electrode ear 11 and the negative electrode ear 12 are arranged opposite to each other.

[0052] The battery cell mainly works by the movement of metal ions between the positive electrode sheet 1 and the negative electrode sheet 2. At least two sheets of hot-melt sealant 4 are arranged between the positive electrode ear 11 and the shell. The multiple sheets of hot-melt sealant 4 are arranged from top to bottom, and a gap 6 is formed between two adjacent sheets of hot-melt sealant 4. The positive electrode ear 11 and the shell are bonded by the hot-melt sealant 4.

[0053] At least two sheets of hot melt sealant 4 are arranged between the negative electrode ear 12 and the shell. The multiple sheets of hot melt sealant 4 are arranged from top to bottom, and a gap 6 is formed between two adjacent sheets of hot melt sealant 4. The negative electrode ear 12 and the shell are bonded by the hot melt sealant 4.

[0054] Furthermore, the length of the hot melt sealant 4 is smaller than the length of the shell.

[0055] Furthermore, the width of the hot melt sealant 4 is in the range of 5 mm to 8 mm.

[0056] Furthermore, the shell is an aluminum-plastic film 5, the positive electrode sheet 1 and the negative electrode sheet 2 are stacked in sequence, and the separator 3 is arranged between adjacent positive electrode sheets 1 and negative electrode sheets 2;

[0057] The positive electrode tab 11 and the negative electrode tab 12 are arranged opposite to each other and are both exposed from the diaphragm 3;

[0058] The aluminum-plastic film 5 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 5;

[0059] The electrolyte includes sodium hexafluorophosphate and an organic solvent.

[0060] Furthermore, the number of the positive electrode sheet 1 is less than that of the negative electrode sheet 2 .

[0061] Furthermore, the separator 3 is arranged outside the outermost negative electrode sheet 2 .

[0062] Furthermore, the diaphragm 3 is a single piece.

[0063] In the prior art, a battery cell of BT120888699, a capacity of 600Ah, a top seal length of 1200mm, and a width of 10mm is made. The traditional method uses a hot melt sealant 4 with a size of 868mm*8mm.

[0064] In the present invention, a battery cell of BT120888699, a capacity of 600Ah, a top seal length of 1200mm, and a width of 10mm is made.

[0065] Two pieces of hot melt sealant 4 with a size of 430 mm*8 mm are used, and a gap 6 between the two pieces is 8 mm.

[0066] Performance comparison between the top seal packaging product of the present invention and the top seal packaging product of the prior art:

[0067]

Claims

1. A battery cell, comprising a housing, an electrode assembly and an electrolyte, wherein the housing is used to contain the electrode assembly and the electrolyte, The electrode assembly (7) is composed of a positive electrode sheet (1), a negative electrode sheet (2) and a separator (3). The electrode assembly (7) is provided with a positive electrode ear (11) and a negative electrode ear (12). The positive electrode ear (11) and the negative electrode ear (12) extend out of the housing respectively, and the positive electrode ear (11) and the negative electrode ear (12) are arranged opposite to each other. The invention is characterized in that: At least two sheets of hot-melt sealant (4) are arranged between the positive electrode tab (11) and the shell, and the multiple sheets of hot-melt sealant (4) are arranged from top to bottom, and a gap (6) is formed between two adjacent sheets of hot-melt sealant (4), and the positive electrode tab (11) and the shell are bonded by the hot-melt sealant (4); At least two sheets of hot-melt sealant (4) are arranged between the negative electrode ear (12) and the shell, and the multiple sheets of hot-melt sealant (4) are arranged from top to bottom, and a gap (6) is formed between two adjacent sheets of hot-melt sealant (4). The negative electrode ear (12) and the shell are bonded together by the hot-melt sealant (4).

2. The battery cell according to claim 1, characterized in that: The length of the hot melt sealant (4) is shorter than the length of the shell.

3. The battery cell according to claim 1, characterized in that: The width of the hot melt sealant (4) is in the range of 5 mm to 8 mm.

4. The battery cell according to claim 1, characterized in that: The shell is an aluminum-plastic film (5), the positive electrode sheets (1) and the negative electrode sheets (2) are stacked in sequence, and the separator (3) is provided between adjacent positive electrode sheets (1) and negative electrode sheets (2); The positive electrode tab (11) and the negative electrode tab (12) are arranged opposite to each other and are both exposed from the diaphragm (3); The aluminum-plastic film (5) 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 (5).

5. The battery cell according to claim 4, characterized in that: The number of the positive electrode sheet (1) is one less than that of the negative electrode sheet (2).

6. The battery cell according to claim 4, characterized in that: The separator (3) is arranged outside the outermost negative electrode sheet (2).

7. The battery cell according to claim 4, characterized in that: The diaphragm (3) is a single piece.

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