A method for preparing lithium-ion battery using gel electrolyte

Abstract

A method for preparing a lithium-ion battery using a gel electrolyte comprises the following steps: stirring fluoroethylene carbonate (FEC), trifluoroethyl methyl carbonate (FEMC), a 1.1.2.2-tetrafluoroethyl 2.2.3.3-tetrafluoropropyl ether (FEPE) solution, and lithium bis(trifluoromethylsulfonyl)imide (LITFS) until completely dissolved and the solution becomes transparent; uniformly mixing the mixture with a transparent solution prepared from ethylthiotetrazolium (ETT), bis(ethylmercaptan) (DODT), and dihydroxymethylpropionic acid (DMPA); then using a pipette to draw the dissolved transparent solution, placing the solution in a groove mold, and forming an electrolyte membrane; and then assembling the electrolyte membrane with a positive lithium sheet and a negative lithium sheet to form a steel-shell battery. The prepared gel electrolyte membrane is easy to form, has a simple processing process, is convenient for large-scale industrial production, and effectively improves production efficiency.

Description

Technical field

[0001] The present invention relates to the technical field of lithium ion battery processing, in particular to a method for preparing a lithium ion battery by using a gel electrolyte. [Background Technology]

[0002] Compared with lead-acid batteries, nickel-metal hydride batteries, and nickel-cadmium batteries, lithium-ion batteries have the advantages of higher energy density, low self-discharge, and long cycle life. They are currently widely used in consumer electronics and power battery fields.

[0003] However, most existing lithium-ion batteries use liquid electrolytes, typically composed of an organic solvent and a lithium salt. These organic solvents have drawbacks such as volatility, flammability, and explosiveness. Furthermore, during thermal runaway in lithium-ion batteries, the liquid electrolyte participates in most of the reactions, ultimately leading to thermal runaway due to combustion of the liquid electrolyte. Therefore, the use of liquid electrolytes in lithium-ion batteries poses significant safety risks. [Summary of the invention]

[0004] The embodiment of the present invention provides a method for preparing a lithium-ion battery using a gel electrolyte. The gel electrolyte is used to replace the traditional liquid electrolyte. By preparing a formed gel electrolyte membrane, the process is simple and convenient, and the process is flame retardant and can effectively reduce electrolyte leakage and improve battery safety. It also has good wettability and good interface contact, effectively solving the flammability and explosiveness problems of traditional liquid electrolyte batteries and improving battery safety.

[0005] A method for preparing a lithium-ion battery using a gel electrolyte according to an embodiment of the present invention comprises the following steps:

[0006] A method for preparing a lithium ion battery using a gel electrolyte comprises the following steps:

[0007] S1, fluoroethylene carbonate FEC, trifluoroethyl methyl carbonate FEMC, 1.1.2.2-tetrafluoroethyl 2.2.3.3-tetrafluoropropyl ether FEPE solution are mixed in a mass ratio of 1:2:1 to form a mixed solution;

[0008] S2. Then, lithium bis(trifluoromethylsulfonyl)imide LITFS, accounting for 20% by mass of the total solution, is added to a mixed solution of fluoroethylene carbonate FEC, trifluoroethyl methyl carbonate FEMC, and 1.1.2.2-tetrafluoroethyl 2.2.3.3-tetrafluoropropyl ether FEPE, and stirred until the mixture is completely dissolved and the solution becomes transparent;

[0009] S3. Then, turn off the light, mix ethylthiotetrazolyl ETT, bis(ethylmercaptan) DODT, and dimethylolpropionic acid DMPA solution in a mass ratio of 15:10:1 to form a mixed solution, and stir until the solution is completely dissolved and transparent:

[0010] S4, uniformly dissolving and mixing the transparent solutions in step S2 and step S3 in a volume ratio of 1:1, then using a pipette to draw the dissolved transparent solution, placing it in a groove mold with a shape set according to the requirements, and shaking the mold to evenly spread the solution;

[0011] S5. Wrap the solution in the mold with tin foil, place a light-shielding box on the mold, place a UV lamp on it, and irradiate it with UV light until the electrolyte membrane is formed;

[0012] S6. Place the positive electrode steel shell upside down on the work surface, first place the positive electrode lithium sheet in the middle of the positive electrode steel shell, then slowly lower the electrolyte membrane from the edge of the steel shell and overlap it tightly with the positive electrode lithium sheet, then place the negative electrode lithium sheet tightly on the electrolyte membrane, and further overlap the steel sheet on the negative electrode lithium sheet, finally cover the negative electrode steel shell and assemble it on the open part of the positive electrode steel shell to complete the assembly of the battery, and finally place the assembled battery on the packaging machine to package and fix it.

[0013] One or more technical solutions provided in the embodiments of the present invention have at least the following technical effects or advantages:

[0014] The process is simple and convenient to process. It is flame retardant and can effectively reduce electrolyte leakage and improve battery safety. It also has good wettability and good interface contact, effectively solving the flammability and explosiveness problems of traditional liquid electrolyte batteries and improving battery safety.

[0015] Gel electrolyte is used to replace traditional liquid electrolyte. By preparing a shaped gel electrolyte membrane, not only is the flame retardant effect good, but the electrolyte is also easy to shape, convenient for processing in industrial production, and has little restriction on shape requirements. It can be processed into batteries of any shape, which can effectively improve production efficiency.

[0016] Moreover, the prepared gel electrolyte membrane has good interface contact properties, which makes it easy to place between the positive and negative lithium sheets. All raw materials are then tightly sealed, which effectively solves the flammability and explosiveness problems of traditional liquid electrolyte batteries. It can also effectively reduce electrolyte leakage and effectively improve battery safety.

Brief Description of the Drawings

[0017] Figure 1 Schematic diagram of the explosion structure of a battery prepared in an embodiment of the present invention. [Specific implementation method]

[0018] The present invention will be further described below with reference to specific examples.

[0019] A method for preparing a lithium ion battery using a gel electrolyte comprises the following steps:

[0020] S1, fluoroethylene carbonate FEC, trifluoroethyl methyl carbonate FEMC, 1.1.2.2-tetrafluoroethyl 2.2.3.3-tetrafluoropropyl ether FEPE solution are mixed in a mass ratio of 1:2:1 to form a mixed solution;

[0021] S2. Then, lithium bis(trifluoromethylsulfonyl)imide LITFS, accounting for 20% by mass of the total solution, is added to a mixed solution of fluoroethylene carbonate FEC, trifluoroethyl methyl carbonate FEMC, and 1.1.2.2-tetrafluoroethyl 2.2.3.3-tetrafluoropropyl ether FEPE, and stirred until the mixture is completely dissolved and the solution becomes transparent;

[0022] S3. Then, turn off the light, mix ethylthiotetrazolyl (ETT), bis(ethylmercaptan) (DODT), and dimethylolpropionic acid (DMPA) solution in a mass ratio of 15:10:1 to form a mixed solution, and stir until the solution is completely dissolved and transparent;

[0023] S4, uniformly dissolving and mixing the transparent solutions in step S2 and step S3 in a volume ratio of 1:1, then using a pipette to draw the dissolved transparent solution, placing it in a groove mold with a shape set according to the requirements, and shaking the mold to evenly spread the solution;

[0024] S5. Wrap the solution in the mold with tin foil to effectively shield it from light and prevent photoinduced polymerization. Then place a light-shielding box on the mold, place a UV lamp on it, and irradiate it with UV light until the electrolyte membrane is formed.

[0025] S6, such as Figure 1 As shown, the positive electrode steel shell 1 is turned upside down on the work surface, the positive electrode lithium sheet 2 is first placed in the middle of the positive electrode steel shell 1, and then the electrolyte membrane 3 is slowly lowered from the edge of the steel shell and tightly overlapped with the positive electrode lithium sheet 2. Then, the negative electrode lithium sheet 4 is tightly placed on the electrolyte membrane 3, and the steel sheet 5 is further overlapped on the negative electrode lithium sheet 4. Finally, the negative electrode steel shell cover 6 is assembled on the open part of the positive electrode steel shell 1 to complete the assembly of the battery. Finally, the assembled battery is placed on the packaging machine and sealed and fixed.

[0026] This preparation method uses gel electrolyte to replace traditional liquid electrolyte. By preparing a shaped gel electrolyte membrane, it is easy to shape, has simple processing technology, is convenient for large-scale industrial production, and has few restrictions on shape requirements. It can be processed into batteries of any shape, which can effectively improve production efficiency.

[0027] Moreover, the gel electrolyte membrane is flame retardant and can effectively reduce electrolyte leakage and improve battery safety. It also has good wettability and good interface contact, effectively solving the flammability and explosiveness problems of traditional liquid electrolyte batteries and improving battery safety.

[0028] The above-described embodiments are merely preferred embodiments of the present invention and are not intended to limit the scope of implementation of the present invention. Except for the cases listed in the specific embodiments, all equivalent changes made according to the methods and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A method for preparing a lithium ion battery using a gel electrolyte, characterized in that: The following steps are involved: S1. Fluoroethylene carbonate FEC, trifluoroethyl methyl carbonate FEMC, and 1.1.2.2-tetrafluoroethyl 2.2.3.3-tetrafluoropropyl ether FEPE solution are mixed in a mass ratio of 1:2:1 to form a mixed solution: S2. Then, lithium bis(trifluoromethylsulfonyl)imide LITFS, accounting for 20% by mass of the total solution, is added to the mixed solution of fluoroethylene carbonate FEC, trifluoroethyl methyl carbonate FEMC, and 1.1.2.2-tetrafluoroethyl 2.2.3.3-tetrafluoropropyl ether FEPE, and stirred until the mixture is completely dissolved and the solution becomes transparent. S3. Then, turn off the light, mix ethylthiotetrazolyl ETT, bis(ethylmercaptan) DODT, and dimethylolpropionic acid DMPA solution in a mass ratio of 15:10:1 to form a mixed solution, and stir until the solution is completely dissolved and transparent: S4, uniformly dissolving and mixing the transparent solutions in step S2 and step S3 in a volume ratio of 1:1, then using a pipette to draw the dissolved transparent solution, placing it in a groove mold with a shape set according to the requirements, and shaking the mold to evenly spread the solution; S5. Wrap the solution in the mold with tin foil, place a light-shielding box on the mold, place a UV lamp on it, and irradiate it with UV light until the electrolyte membrane is formed; S6. Place the positive electrode steel shell upside down on the work surface, first place the positive electrode lithium sheet in the middle of the positive electrode steel shell, then slowly lower the electrolyte membrane from the edge of the steel shell and overlap it tightly with the positive electrode lithium sheet, then place the negative electrode lithium sheet tightly on the electrolyte membrane, and further overlap the steel sheet on the negative electrode lithium sheet, finally cover the negative electrode steel shell and assemble it on the open part of the positive electrode steel shell to complete the assembly of the battery, and finally place the assembled battery on the packaging machine to package and fix it.

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