A manufacturing process for gel electrolyte battery

Abstract

The invention discloses a manufacturing process for a gel electrolyte battery. The process comprises the following steps: adding an initiator to an electrolyte containing 0-8% of a polymer monomer during battery injection; adding a liquid electrolyte until the interface of the gel electrolyte and the interface of the electrode are in full contact after the electrolyte undergoes a curing process to form a gel electrolyte and undergoes a chemical formation process; and allowing the process to stand for subsequent processes. The curing process involves curing the electrolyte into a gel electrolyte under high-temperature pressurized conditions or high-temperature conditions; and the chemical formation process is performed after the electrolyte has been cured into the gel electrolyte. Compared with the prior art, the present invention utilizes a secondary injection and intermediate curing method to reasonably complete the gelation of the electrolyte and realize the function of the gel electrolyte while ensuring battery performance, while optimizing the electrode interface, thereby ensuring battery performance and improving battery safety.

Description

Technical Field

[0001] The present invention relates to the field of lithium ion battery production technology, in particular to a gel electrolyte battery manufacturing process. Background Art

[0002] Since the 21st century, people have placed increasing hope on advances in new energy technologies to alleviate the current shortage of non-renewable resources, such as oil. Lithium-ion batteries are particularly popular due to their high energy density, sustained energy output, and environmental compliance. However, their safety remains a major concern. Traditional liquid electrolytes pose a risk of leakage, posing safety risks such as combustion and even explosion during use. Consequently, numerous researchers and commercial engineers have adopted solid-state electrolytes as an alternative to liquid electrolytes to improve the safety of lithium-ion batteries. However, under existing technologies, impedance and interfacial reactions at the positive and negative electrode-electrolyte interfaces degrade battery electrochemical performance, becoming a key bottleneck in the development of all-solid-state batteries. To overcome these bottlenecks, numerous researchers have devoted themselves to the development of semi-solid-state batteries. For example, gel polymer electrolytes are developed by adding polymer monomers to the electrolyte system and polymerizing them under heating to form a gel-like solid electrolyte. The polymer network absorbs some of the electrolyte, reducing the amount of mobile electrolyte components in the battery, minimizing the risk of electrolyte leakage, and improving battery safety. At the same time, the battery interface is good and the battery electrochemical performance is stable. However, in the existing technology, there will be gaps between the gel-like solid electrolyte interface and the electrode interface, which cannot be fully contacted and the performance of the battery cell cannot be guaranteed. Summary of the Invention

[0003] The present invention aims to provide a gel electrolyte battery manufacturing process, in which a small amount of conventional liquid electrolyte is added after formation so that the gel electrolyte interface and the electrode interface can be more fully contacted to ensure the electrical performance of the battery cell.

[0004] In order to achieve the above object, the technical solution of the present invention is:

[0005] A gel electrolyte battery manufacturing process includes adding an initiator to an electrolyte containing 0-8% polymer monomer during battery filling; after the electrolyte undergoes a solidification process to form a gel electrolyte and a formation process, liquid electrolyte is added until the gel electrolyte interface and the electrode interface are in full contact; and the battery is left to stand for subsequent processes.

[0006] The curing process is to solidify the electrolyte into a gel electrolyte under high temperature and pressure conditions or high temperature conditions; the chemical conversion process is carried out after the electrolyte is solidified into the gel electrolyte.

[0007] Furthermore, the initiator is one or more of azobisisobutyronitrile, azobisisovaleronitrile, azobisisoheptanenitrile, and dimethyl azobisisobutyrate.

[0008] Furthermore, the initiator content is 0-0.1% by weight of the electrolyte content.

[0009] Furthermore, the components of the electrolyte include 0-25% dimethyl carbonate, 25-55% ethyl methyl carbonate, 20-40% ethylene carbonate, and the lithium salt content is 10-12%.

[0010] Furthermore, the lithium salt is LiPF6.

[0011] Furthermore, the electrolyte also includes 0-4% LiFSI, 0-2% vinylene carbonate, and 0-2% 1,3-propane sultone.

[0012] Furthermore, the polymer monomer is one or more of polyethylene glycol, pentaerythritol triacrylate, ethoxylated trimethylolpropane triacrylate, benzoyl peroxide, lauroyl peroxide, methyl ethyl ketone peroxide, cyclohexanone peroxide, tert-butyl perbenzoate, dimethacrylate, N,N'-dimethylacrylamide, N,N'-diethylacrylamide, N,N'-methylenebisacrylamide, allyl acetoacetate, and acrylonitrile, and the molecular weight of the dimethacrylate is 550-6000.

[0013] Furthermore, the formation process is performed at room temperature or high temperature, and the pressure is maintained at 0-0.5 MPa during the formation.

[0014] Furthermore, during high temperature formation, the temperature is maintained at 45°C-80°C.

[0015] Compared with the prior art, the present invention has the following advantages and positive effects:

[0016] Compared with the prior art, the present invention uses a secondary liquid injection and intermediate solidification method to reasonably complete the gelation of the electrolyte and realize the function of the gel electrolyte while ensuring battery performance, and optimize the electrode interface, thereby ensuring battery performance and improving battery safety. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0018] Figure 1A comparison chart of the capacity of the battery cell of the present invention and the capacity of the liquid electrolyte battery;

[0019] Figure 2 This is a charge and discharge curve diagram of the battery cell of the present invention;

[0020] Figure 3 This is the charge and discharge curve of the liquid electrolyte battery. DETAILED DESCRIPTION

[0021] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0022] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating directions or positional relationships, are based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the devices or components referred to must have a specific direction, be constructed and operated in a specific direction, and therefore should not be understood as limiting the present invention; the terms "first", "second", and "third" are only used for descriptive purposes and should not be understood as indicating or implying relative importance. In addition, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" 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, an indirect connection through an intermediate medium, or it can be internal communication between two components. For those skilled in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0023] like Figure 1-Figure 3 As shown,

[0024] Example 1:

[0025] This embodiment is a soft-pack battery. After the battery cells are stacked, packaged and baked, they are injected with electrolyte. The electrolyte is an organic solvent system containing 8% pentaerythritol triacrylate polymer monomer, lithium salt of lithium hexafluorophosphate, and 0.04% azobisisobutyronitrile initiator. The total injection volume is 55g. After the injection is completed, vacuum sealing is performed. After the battery is left to stand for 24 hours, it is placed on a device with a pressure of 0.2MPa and cured at 60°C for 8 hours. Then, low-current formation is performed at a pressure of 0.2MPa, and the temperature is maintained at 55°C during formation. After formation, 5g of electrolyte is added. The battery is left to stand at room temperature for 24 hours, and then vacuum-packaged. The battery cells are then tested. In the safety test, the test sample is charged at a constant current of 20A until the voltage reaches 1.5 times the charge termination voltage specified in the enterprise technical conditions, and charging is stopped. The battery does not catch fire or smoke.

[0026] In this embodiment, the components of the electrolyte include 0~25% dimethyl carbonate, 25%~55% ethyl methyl carbonate, 20%~40% ethylene carbonate, the lithium salt content is 10%~12%, and it also includes 0~4% LiFSI, 0~2% vinylene carbonate, and 0~2% 1,3-propane sultone;.

[0027] Example 2:

[0028] This embodiment is a hard-shell battery. The battery cell is wound, packaged, and baked before being injected with electrolyte. The electrolyte is an organic solvent system containing lithium hexafluorophosphate as the lithium salt, containing 10% benzoyl peroxide polymer monomer. The injection volume is 110g. After the injection is completed, a sealing nail is inserted. After the battery is left to stand for 24 hours, it is cured at 60°C for 8 hours, and then formed at 55°C. After formation, a second injection is performed, with an injection volume of 10g. After sealing with a sealing nail, the battery is left to stand at room temperature for 24 hours. The injection hole is cleaned with DMC, and the battery cell is then tested. During the safety test, the test sample is charged at a constant current of 20A until the voltage reaches 1.5 times the charge termination voltage specified in the enterprise technical conditions, and then charging is stopped. The battery did not catch fire or smoke.

[0029] In this embodiment, the components of the electrolyte are the same as those in Example 1.

[0030] Comparative Example 1:

[0031] This comparative example involves a soft-pack battery. After lamination, packaging, and baking, the cells were filled with electrolyte. The electrolyte consisted of an organic solvent system containing 8% pentaerythritol triacrylate polymer monomer as a lithium salt of lithium hexafluorophosphate. The total injection volume was 60g. After the filling was complete, the cells were vacuum-sealed. After standing for 24 hours, the cells were formed at a low current at 0.2MPa pressure and 45°C. After standing for 24 hours at room temperature, the cells were vacuum-sealed and tested. During safety testing, the test samples were charged at a constant current of 20A until the voltage reached 1.5 times the charge termination voltage specified in the company's technical specifications. Charging was stopped, and the battery ignited.

[0032] Comparative Example 2:

[0033] This comparative example is a hard-shell battery. The battery cell is wound, packaged, and baked before being injected with electrolyte. The electrolyte is an organic solvent system containing lithium hexafluorophosphate as lithium salt and 10% benzoyl peroxide polymer monomer. The total injection volume is 110 g. After the injection is completed, a sealing nail is inserted. After the battery is left to stand for 24 hours, it is cured at 60°C for 8 hours and then formed at 55°C. After formation, a second injection is performed with an injection volume of 10 g. After sealing with a sealing nail, the battery is left to stand at room temperature for 24 hours. The injection hole is cleaned with DMC and the battery cell is then tested. In the safety test, the test sample is charged at a constant current of 20 A until the voltage reaches 1.5 times the charge termination voltage specified in the enterprise technical conditions, and then charging is stopped. The battery begins to smoke.

[0034] After testing: Figure 1 、 Figure 2 、 Figure 3 The figure shows a comparison of the battery capacity and charge-discharge curves of the gel electrolyte and the liquid electrolyte. It can be concluded that the gel electrolyte battery capacity of Example 1 and Example 2 is the same as that of the liquid electrolyte battery, the curves are similar, and the interface is good.

[0035] In terms of battery safety, the test results of Example 1, Comparative Example 1, Example 2, and Comparative Example 2 are as follows:

[0036]

[0037] Compared with the prior art, the present invention uses a secondary liquid injection and intermediate solidification method to reasonably complete the gelation of the electrolyte and realize the function of the gel electrolyte while ensuring battery performance, and optimize the electrode interface, thereby ensuring battery performance and improving battery safety.

[0038] Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative work, any modifications, equivalent substitutions, improvements, etc. made should be included in the scope of protection of the present invention.

Claims

1. A gel electrolyte battery manufacturing process, characterized in that: When filling the battery, an initiator is added to the electrolyte containing 0-8% polymer monomer; after the electrolyte undergoes a solidification process to form a gel electrolyte and a formation process, liquid electrolyte is added until the gel electrolyte interface and the electrode interface are fully in contact; and the battery is left to stand for subsequent processes; The curing process is to solidify the electrolyte into a gel electrolyte under high temperature and pressure conditions or high temperature conditions; the formation process is carried out after the electrolyte is solidified into the gel electrolyte; The initiator is one or more of azobisisobutyronitrile, azobisisovaleronitrile, azobisisoheptanenitrile, and dimethyl azobisisobutyrate; The initiator content is 0-0.1% by weight of the electrolyte content.

2. The process for manufacturing a gel electrolyte battery according to claim 1, wherein: The components of the electrolyte include 0-25% dimethyl carbonate, 25-55% ethyl methyl carbonate, 20-40% ethylene carbonate, and a lithium salt content of 10-12%.

3. The process for manufacturing a gel electrolyte battery according to claim 2, wherein: The lithium salt is LiPF6.

4. The process for manufacturing a gel electrolyte battery according to claim 1, wherein: The electrolyte further includes 0-4% of LiFSI, 0-2% of vinylene carbonate, and 0-2% of 1,3-propane sultone.

5. The process for manufacturing a gel electrolyte battery according to claim 1, wherein: The polymer monomer is one or more of polyethylene glycol, pentaerythritol triacrylate, ethoxylated trimethylolpropane triacrylate, benzoyl peroxide, lauroyl peroxide, methyl ethyl ketone peroxide, cyclohexanone peroxide, tert-butyl perbenzoate, dimethacrylate, N,N'-dimethylacrylamide, N,N'-diethylacrylamide, N,N'-methylenebisacrylamide, allyl acetoacetate, and acrylonitrile, and the molecular weight of the dimethacrylate is 550-6000.

6. The process for manufacturing a gel electrolyte battery according to claim 5, characterized in that: The forming process is performed at room temperature or high temperature, and the pressure is maintained at 0-0.5Mpa during the forming process.

7. The process for manufacturing a gel electrolyte battery according to claim 6, characterized in that: During high temperature forming, the temperature is maintained at 45℃-80℃.

Images