Gel electrolyte, preparation method and lithium ion battery
By in-situ intercalating two-dimensional layered nanosheets into a gel electrolyte within a polymer matrix, the thermal stability and electrochemical performance issues of lithium-ion battery electrolyte solvents were resolved, resulting in a lithium-ion battery with high safety and high performance.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- CHONGQING UNIV OF TECH
- Filing Date
- 2022-11-04
- Publication Date
- 2026-08-04
AI Technical Summary
Existing lithium-ion batteries have electrolyte solvents with low thermal stability, making them flammable and explosive, which leads to safety issues. At the same time, improving safety would sacrifice the battery's electrochemical performance, and the ion transport number and ionic conductivity of the electrolyte are difficult to meet commercial requirements.
A gel electrolyte was prepared by using a polymer matrix with uniform in-situ intercalation of two-dimensional layered nanosheets and an electrolyte solution loaded on it, including an organic electrolyte lithium salt and a vinylene carbonate solvent, through ultrasonic vibration treatment and liquid phase exfoliation, thereby improving the ionic conductivity and interfacial compatibility of the electrolyte.
It improves the thermodynamic and electrochemical stability of lithium-ion batteries, broadens the operating voltage and temperature range, enhances battery safety and electrochemical performance, and meets commercial requirements.
Smart Images
Figure CN115911516B_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of battery technology, specifically relating to a gel electrolyte, its preparation method, and a lithium-ion battery. Background Technology
[0002] The development of new energy vehicles, large-scale energy storage, aerospace, and national defense has placed higher demands on the comprehensive performance of lithium-ion batteries. While focusing on the energy density and power characteristics of lithium-ion batteries, safety and environmental adaptability have also been key factors affecting their widespread and effective application.
[0003] Electrolyte materials play a role in transporting and conducting electrons between the positive and negative electrodes. Their performance not only affects the normal performance of electrode materials (such as specific capacity, cycle life and rate performance), but also has a great impact on battery safety.
[0004] The electrolyte solvents used in commercial lithium-ion batteries have shortcomings such as low thermal stability and flammability and explosiveness, which can easily cause thermal runaway of lithium-ion batteries, resulting in adverse consequences such as fire or even explosion.
[0005] In existing technologies, flame-retardant additives such as ionic liquids are mainly added to organic electrolytes to reduce the above-mentioned adverse consequences. However, while this method improves the safety of lithium-ion batteries, it comes at the cost of sacrificing the battery's electrochemical performance, and the degree of improvement in battery safety is limited. Summary of the Invention
[0006] This application provides a gel electrolyte, a preparation method, and a lithium-ion battery, which broadens the working voltage and operating temperature range of the electrolyte while solving the technical problem that the ion transport number and ionic conductivity of the gel electrolyte are difficult to meet commercial requirements.
[0007] To achieve the above objectives, the technical solutions adopted in the embodiments of this application are as follows:
[0008] In a first aspect, embodiments of this application provide a gel electrolyte, comprising a polymer matrix uniformly and in situ intercalated with two-dimensional layered nanosheets and an electrolyte solution loaded in the polymer matrix, wherein the solute of the electrolyte solution comprises an organic electrolyte lithium salt and the solvent of the electrolyte solution comprises vinylene carbonate.
[0009] In an optional embodiment, the polymer substrate includes any one of polyvinylidene fluoride-hexafluoropropylene copolymer, polyethylene oxide, and polypropylene carbonate.
[0010] In an optional embodiment, the number-average molecular weight of the polyvinylidene fluoride-hexafluoropropylene copolymer is 400,000, the number-average molecular weight of the polyethylene oxide is 600,000, and the number-average molecular weight of the polypropylene carbonate is 50,000.
[0011] In an optional embodiment, the two-dimensional layered nanosheets include any one of the following structures: layered metal double hydroxides and layered metal double oxides, with a particle size of less than 100 nm and an interlayer distance of less than 1 nm.
[0012] In an optional embodiment, the content of the two-dimensional layered nanosheets is 0.1%-0.5wt% based on the solid electrolyte membrane substrate, and the thickness is 50-200µm.
[0013] In an optional embodiment, the organoelectrolyte lithium salt comprises lithium bis(trifluoromethanesulfonyl)imide, and the concentration of the vinylene carbonate is 1 mol / L.
[0014] In an optional embodiment, the gel electrolyte has an ionic conductivity greater than 1.36 × 10⁻³ S / cm, an ion transference number of 0.83, and an electrochemical stability window greater than 4.8 V.
[0015] Secondly, embodiments of this application provide a method for preparing a gel electrolyte, used to prepare the gel electrolyte of any of the above. The two-dimensional layered nanosheets are added to a pre-prepared polymer mixture solution at a certain mass fraction and subjected to ultrasonic vibration treatment until the two-dimensional layered nanosheets are uniformly intercalated in situ into the polymer molecular chain network to obtain a mixture containing two-dimensional layered nanosheets. A two-dimensional layered in situ intercalated polymer substrate of the target thickness is obtained based on the liquid phase exfoliation method. The polymer substrate is placed in a certain concentration of bis(trifluoromethanesulfonyl)imide lithium electrolyte solution for saturated absorption until the mass no longer changes before and after immersion. The solution on the surface is removed and dried to obtain a two-dimensional layered nanosheet in situ intercalated gel electrolyte.
[0016] In an optional embodiment, the pre-prepared polymer mixture solution is prepared by dissolving a dried and dehydrated polymer in a mixed solution of N'N-dimethylformamide and glycerol, heating and stirring until dissolved. The polymer includes any one of polyvinylidene fluoride-hexafluoropropylene copolymer, polyethylene oxide, and polypropylene carbonate. The drying conditions are a drying temperature of 60-80°C and a drying time of 1-2 hours; the stirring temperature is 50-60°C and the stirring time is 12-15 hours.
[0017] Thirdly, embodiments of this application provide a lithium-ion battery, including the gel electrolyte described in any of the above claims, wherein the lithium-ion battery has an initial charge / discharge capacity greater than 140 mAh / g at 0.1C, a capacity retention rate greater than or equal to 92.4% after 100 charge / discharge cycles at 0.2C, a charge / discharge efficiency greater than or equal to 96%, and a charging capacity greater than or equal to 96.5% after cycling at different rates.
[0018] In the technical solution provided in this application embodiment, a novel gel electrolyte is obtained by in-situ intercalating two-dimensional layered nanosheets into a polymer substrate. Utilizing the in-situ pore-expanding effect of the two-dimensional layered nanosheets and the interlayer ion exchange properties of layered double hydroxides and layered double oxides, the ionic conductivity of the gel electrolyte is improved, achieving a conductivity of 10. -3 The S / m usage requirements. Meanwhile, the gel electrolyte modified by in-situ intercalation of two-dimensional layered nanosheets can effectively improve the interfacial compatibility between the electrolyte and the negative electrode, preventing dendrites formed by lithium ion deposition from piercing the passivation film, directly improving the thermodynamic and electrochemical stability of the gel electrolyte, and widening the battery's operating voltage and temperature range. Attached Figure Description
[0019] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0020] Figure 1 This is a schematic diagram of the preparation method of the gel electrolyte provided in the embodiments of this application;
[0021] Figure 2 This is the DSC curve of the gel electrolyte provided in the embodiments of this application;
[0022] Figure 3 This is a graph showing the electrochemical performance of the gel electrolyte provided in the embodiments of this application. Detailed Implementation
[0023] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Where specific conditions are not specified in the embodiments, conventional conditions or conditions recommended by the manufacturer shall apply. Reagents or instruments whose manufacturers are not specified are all conventional products that can be purchased commercially.
[0024] The features and performance of the present invention will be further described in detail below with reference to embodiments.
[0025] The first embodiment of the present invention provides a gel electrolyte, comprising a polymer matrix uniformly intercalated in situ with two-dimensional layered nanosheets and an electrolyte solution loaded in the polymer matrix, wherein the solute of the electrolyte solution comprises an organic electrolyte lithium salt and the solvent of the electrolyte solution comprises vinylene carbonate.
[0026] The second embodiment of the present invention provides a method for preparing a gel electrolyte. The main process is to add the two-dimensional layered nanosheets to a pre-prepared polymer mixture solution at a certain mass fraction and perform ultrasonic vibration treatment until the two-dimensional layered nanosheets are uniformly intercalated in situ into the polymer molecular chain network to obtain a mixture containing two-dimensional layered nanosheets. A two-dimensional layered in situ intercalated polymer substrate of the target thickness is obtained based on the liquid phase exfoliation method. The polymer substrate is placed in a certain concentration of bis(trifluoromethanesulfonyl)imide lithium electrolyte solution for saturated absorption until the mass no longer changes before and after immersion. The solution on the surface is removed and dried to obtain a two-dimensional layered nanosheet in situ intercalated gel electrolyte.
[0027] The third embodiment of the present invention provides a lithium-ion battery, including a gel electrolyte obtained by the preparation method. The lithium-ion battery based on this gel electrolyte structure has an initial charge-discharge capacity of more than 140 mAh / g at 0.1C, a capacity retention of more than or equal to 92.4% after 100 charge-discharge cycles at 0.2C, a charge-discharge efficiency of more than or equal to 96%, and a charging capacity of more than or equal to 96.5% after cycling at different rates.
[0028] In the gel electrolyte, gel electrolyte, and lithium-ion battery provided in this embodiment, the polymer substrate includes any one of polyvinylidene fluoride-hexafluoropropylene copolymer, polyethylene oxide, and polypropylene carbonate. Each different polymer substrate has a different molecular weight; specifically, the number average molecular weight of polyvinylidene fluoride-hexafluoropropylene copolymer is 400,000, the number average molecular weight of polyethylene oxide is 600,000, and the number average molecular weight of polypropylene carbonate is 50,000.
[0029] The two-dimensional layered nanosheets include any one of the following structures: layered metal double hydroxides and layered metal double oxides, with a particle size of less than 100 nm and an interlayer distance of less than 1 nm. The content of the two-dimensional layered nanosheets, based on the solid electrolyte membrane substrate, is 0.1 wt%-0.5 wt%, and the thickness is 50-200 μm. Specifically, the two-dimensional layered nanosheets contain hydroxide ions and oxygen ions with ion exchange properties, including but not limited to MgAl-LDH, NiFe-LDH, ZnAl-LDH, NiAl-LDH, NiFe-LDO, and MgAl-LDO, with different mass fractions for different compounds, specifically 0 wt%, 0.1 wt%, 0.2 wt%, 0.3 wt%, 0.4 wt%, and 0.5 wt%.
[0030] In this embodiment, the organic electrolyte lithium salt is specifically lithium bis(trifluoromethanesulfonyl)imide, and the solvent vinylene carbonate concentration of the electrolyte solution is 1 mol / L.
[0031] The specific process control parameters for the preparation method are as follows: drying temperature is 60-80℃, drying time is 1-2 hours, stirring temperature is 50-60℃, and stirring time is 12-15 hours.
[0032] To further illustrate the preparation method of gel electrolytes in detail, this embodiment provides a detailed description of gel electrolytes under different conditions and the control process under different conditions.
[0033] Example 1
[0034] This embodiment describes the preparation of gel electrolytes, which includes the following process:
[0035] (1) Take 1g of glycerol and 10ml of N'N-dimethylformamide and mix them in a 50ml beaker. Dissolve 1g of dried polyvinylidene chloride-hexafluoropropylene copolymer in the above mixed solution and stir at 50℃ for 12 hours to obtain a mixed solution.
[0036] (2) The sample prepared in step (1) was left to stand, transferred to a freeze dryer, and the liquid phase was removed by freeze sublimation to prepare a polyvinylidene chloride-hexafluoropropylene copolymer composite polymer substrate with a pore size of 10 nm.
[0037] (3) Dissolve 2.87g of C2F6LiNO4S2 in 10mL of vinylene carbonate to prepare an electrolyte with a concentration of 1mol / L. Place the composite polymer substrate in the electrolyte for 4h, absorb the saturated liquid, wipe the liquid off the surface, and the polyvinylidene chloride-hexafluoropropylene copolymer gel electrolyte can be obtained.
[0038] Example 2
[0039] This embodiment describes the preparation of gel electrolytes, which includes the following process:
[0040] (1) Take 1g of glycerol and 10ml of N'N-dimethylformamide and mix them in a 50ml beaker. Dissolve 1g of dried polyvinylidene chloride-hexafluoropropylene copolymer in the above mixed solution and stir at 50℃ for 12 hours to obtain a mixed solution.
[0041] (2) Weigh 0.1 wt% of magnesium aluminum layered double hydroxide of polyvinylidene chloride-hexafluoropropylene copolymer and add it to the mixed solution in step (1). Sonicate for 0.5-1 hour to ensure that the magnesium aluminum layered double hydroxide is fully intercalated into the molecular chain network of polyvinylidene chloride-hexafluoropropylene copolymer.
[0042] (3) The sample prepared in step (2) was left to stand, transferred to a freeze dryer, and the liquid phase was removed by freeze sublimation to prepare a magnesium-aluminum layered double hydroxide in situ intercalated polyvinylidene chloride-hexafluoropropylene copolymer composite polymer substrate with a pore size of 7 nm.
[0043] (4) Dissolve 2.87g of C2F6LiNO4S2 in 10mL of vinylene carbonate to prepare an electrolyte with a concentration of 1mol / L. Place the composite polymer substrate in the electrolyte for 4h, allow it to absorb the saturated solution, and wipe the liquid off the surface. This will yield 0.1wt% magnesium-aluminum layered double hydroxide in-situ intercalated polyvinylidene chloride-hexafluoropropylene copolymer.
[0044] Example 3
[0045] This embodiment describes the preparation of gel electrolytes, which includes the following process:
[0046] (1) Take 1g of glycerol and 10ml of N'N-dimethylformamide and mix them in a 50ml beaker. Dissolve 1g of dried polyvinylidene chloride-hexafluoropropylene copolymer in the above mixed solution and stir at 50℃ for 12 hours to obtain a mixed solution.
[0047] (2) Weigh 0.2 wt% of magnesium aluminum layered double hydroxide of polyvinylidene chloride-hexafluoropropylene copolymer and add it to the mixed solution in step (1). Sonicate for 0.5-1 hour to ensure that the magnesium aluminum layered double hydroxide is fully intercalated into the molecular chain network of polyvinylidene chloride-hexafluoropropylene copolymer.
[0048] (3) The sample prepared in step (2) was left to stand, transferred to a freeze dryer, and the liquid phase was removed by freeze sublimation to prepare a magnesium-aluminum layered double hydroxide in situ intercalated polyvinylidene chloride-hexafluoropropylene copolymer composite polymer substrate with a pore size of 7 nm.
[0049] (4) Dissolve 2.87g of C2F6LiNO4S2 in 10mL of vinylene carbonate to prepare an electrolyte with a concentration of 1mol / L. Place the composite polymer substrate in the electrolyte for 4h, allow it to absorb the saturated solution, and wipe the liquid off the surface. This will yield 0.2wt% magnesium-aluminum layered double hydroxide in-situ intercalated polyvinylidene chloride-hexafluoropropylene copolymer.
[0050] Example 4
[0051] This embodiment describes the preparation of gel electrolytes, which includes the following process:
[0052] (1) Take 1g of glycerol and 10ml of N'N-dimethylformamide and mix them in a 50ml beaker. Dissolve 1g of dried polyvinylidene chloride-hexafluoropropylene copolymer in the above mixed solution and stir at 50℃ for 12 hours to obtain a mixed solution.
[0053] (2) Weigh 0.3 wt% of magnesium aluminum layered double hydroxide of polyvinylidene chloride-hexafluoropropylene copolymer and add it to the mixed solution in step (1). Sonicate for 0.5-1 hour to ensure that the magnesium aluminum layered double hydroxide is fully intercalated into the molecular chain network of polyvinylidene chloride-hexafluoropropylene copolymer.
[0054] (3) The sample prepared in step (2) was left to stand, transferred to a freeze dryer, and the liquid phase was removed by freeze sublimation to prepare a magnesium-aluminum layered double hydroxide in situ intercalated polyvinylidene chloride-hexafluoropropylene copolymer composite polymer substrate with a pore size of 7 nm.
[0055] (4) Dissolve 2.87g of C2F6LiNO4S2 in 10mL of vinylene carbonate to prepare an electrolyte with a concentration of 1mol / L. Place the composite polymer substrate in the electrolyte for 4h, allow it to absorb the saturated solution, and wipe the liquid off the surface. This will yield 0.3wt% magnesium-aluminum layered double hydroxide in-situ intercalated polyvinylidene chloride-hexafluoropropylene copolymer.
[0056] Example 5
[0057] This embodiment describes the preparation of gel electrolytes, which includes the following process:
[0058] (1) Take 1g of glycerol and 10ml of N'N-dimethylformamide and mix them in a 50ml beaker. Dissolve 1g of dried polyvinylidene chloride-hexafluoropropylene copolymer in the above mixed solution and stir at 50℃ for 12 hours to obtain a mixed solution.
[0059] (2) Weigh 0.4 wt% of magnesium aluminum layered double hydroxide of polyvinylidene chloride-hexafluoropropylene copolymer and add it to the mixed solution in step (1). Sonicate for 0.5-1 hour to ensure that the magnesium aluminum layered double hydroxide is fully intercalated into the molecular chain network of polyvinylidene chloride-hexafluoropropylene copolymer.
[0060] (3) The sample prepared in step (2) was left to stand, transferred to a freeze dryer, and the liquid phase was removed by freeze sublimation to prepare a magnesium-aluminum layered double hydroxide in situ intercalated polyvinylidene chloride-hexafluoropropylene copolymer composite polymer substrate with a pore size of 7 nm.
[0061] (4) Dissolve 2.87g of C2F6LiNO4S2 in 10mL of vinylene carbonate to prepare an electrolyte with a concentration of 1mol / L. Place the composite polymer substrate in the electrolyte for 4h, allow it to absorb the saturated solution, and wipe the liquid off the surface. This will yield 0.4wt% magnesium-aluminum layered double hydroxide in-situ intercalated polyvinylidene chloride-hexafluoropropylene copolymer.
[0062] Example 6
[0063] This embodiment describes the preparation of gel electrolytes, which includes the following process:
[0064] (1) Take 1g of glycerol and 10ml of N'N-dimethylformamide and mix them in a 50ml beaker. Dissolve 1g of dried polyvinylidene chloride-hexafluoropropylene copolymer in the above mixed solution and stir at 50℃ for 12 hours to obtain a mixed solution.
[0065] (2) Weigh 0.5 wt% of magnesium aluminum layered double hydroxide of polyvinylidene chloride-hexafluoropropylene copolymer and add it to the mixed solution in step (1). Sonicate for 0.5-1 hour to ensure that the magnesium aluminum layered double hydroxide is fully intercalated into the molecular chain network of polyvinylidene chloride-hexafluoropropylene copolymer.
[0066] (3) The sample prepared in step (2) was left to stand, transferred to a freeze dryer, and the liquid phase was removed by freeze sublimation to prepare a magnesium-aluminum layered double hydroxide in situ intercalated polyvinylidene chloride-hexafluoropropylene copolymer composite polymer substrate with a pore size of 7 nm.
[0067] (4) Dissolve 2.87g of C2F6LiNO4S2 in 10mL of vinylene carbonate to prepare an electrolyte with a concentration of 1mol / L. Place the composite polymer substrate in the electrolyte for 4h, allow it to absorb the saturated solution, and wipe the liquid off the surface. This will yield 0.5wt% magnesium-aluminum layered double hydroxide in-situ intercalated polyvinylidene chloride-hexafluoropropylene copolymer.
[0068] Based on the experimental results in Examples 1-6, the ionic conductivity of the gel electrolyte prepared in Example 5 is greater than 1.36 × 10⁻⁶.-3 The S / cm ratio is 0.83, the ion transference number reaches 0.83, and the electrochemical stability window is greater than 4.8V.
[0069] Furthermore, for the gel electrolyte in Example 5, the lithium / LiFePO4 battery was assembled in a glove box in the order of negative electrode shell, spring sheet, lithium sheet, gel electrolyte, positive electrode, and positive electrode shell, and its electrochemical performance was tested.
[0070] Tests showed that the gel electrolyte had an initial charge / discharge capacity greater than 140 mAh / g at 0.1C, and after 100 charge / discharge cycles at 0.2C, the capacity retention and charge / discharge efficiency reached 92.4% and 96%, respectively. The charging capacity remained at 96.5% after cycling at different rates.
[0071] Experimental Example 1
[0072] Temperature experiments were conducted on the gel electrolyte provided in Example 5, and the experimental results were obtained.
[0073] See Figure 2 , Figure 2 The DSC curve of the gel electrolyte obtained by the gel electrolyte preparation method provided in Example 5 was obtained by performing a temperature experiment. Figure 2 It can be seen that the melting temperature of the electrolyte provided in Example 5 is greater than 120°C, which is much higher than the upper limit temperature for battery use. This indicates that the gel electrolyte provided by Shili has high temperature stability, and the thermal stability of lithium-ion batteries can be improved by using this gel electrolyte.
[0074] Experiment Example 2
[0075] Conductivity experiments were conducted on the gel electrolyte provided in Example 5, and the experimental results were obtained.
[0076] See Figure 3 , Figure 3 The electrochemical performance diagram was obtained by conducting conductivity experiments on the gel electrolyte prepared by the gel electrolyte preparation method provided in Example 5. Figure 3 It can be seen that the ion transport number of the gel electrolyte reaches 0.83, and its ionic conductivity is 1.36 × 10⁻⁶. -3 S / cm, reaching commercial-grade 10 -3 S / cm requirement.
[0077] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the principles of the present invention should be included within the protection scope of the present invention.
Claims
1. A method for preparing a gel electrolyte, characterized in that, For preparing a gel electrolyte, the gel electrolyte comprises a polymer matrix uniformly and in situ intercalated with two-dimensional layered nanosheets and an electrolyte solution loaded in the polymer matrix. The solute of the electrolyte solution includes an organic electrolyte lithium salt, and the solvent of the electrolyte solution includes vinylene carbonate. The two-dimensional layered nanosheets include any one of layered metal double hydroxides and layered metal double oxides with a particle size of less than 100 nm and an interlayer distance of less than 1 nm. The layered metal double hydroxides include any one of MgAl-LDH, NiFe-LDH, ZnAl-LDH, and NiAl-LDH, and the layered metal double oxides include any one of NiFe-LDO and MgAl-LDO. The polymer matrix includes any one of polyvinylidene fluoride-hexafluoropropylene copolymer, polyethylene oxide, and polypropylene carbonate. The organic electrolyte lithium salt includes lithium bis(trifluoromethanesulfonyl)imide; the preparation method of the gel electrolyte involves adding the two-dimensional layered nanosheets to a pre-prepared polymer mixture solution at a certain mass fraction and subjecting it to ultrasonic vibration treatment for 0.5-1 hours until the two-dimensional layered nanosheets are uniformly intercalated in situ into the polymer molecular chain network to obtain a mixture containing two-dimensional layered nanosheets; obtaining a two-dimensional layered in-situ intercalated polymer matrix of the target thickness based on the liquid phase exfoliation method; placing the polymer matrix in a lithium bis(trifluoromethanesulfonyl)imide electrolyte solution of a certain concentration for saturated absorption until the mass no longer changes before and after immersion; removing the solution from the surface and drying to obtain the two-dimensional layered nanosheet in-situ intercalated gel electrolyte; the pre-prepared polymer mixture solution is prepared by dissolving the dried and dehydrated polymer in a mixed solution of N'N-dimethylformamide and glycerol and heating and stirring until dissolved.
2. The method for preparing gel electrolyte according to claim 1, characterized in that, The polyvinylidene fluoride-hexafluoropropylene copolymer has a number average molecular weight of 400,000, the polyethylene oxide has a number average molecular weight of 600,000, and the polypropylene carbonate has a number average molecular weight of 50,000.
3. The method for preparing gel electrolyte according to claim 1, characterized in that, The content of the two-dimensional layered nanosheets is 0.1wt%-0.5wt% based on the solid electrolyte membrane substrate.
4. The method for preparing gel electrolyte according to claim 1, characterized in that, The concentration of the lithium bis(trifluoromethanesulfonyl)imide electrolyte solution is 1 mol / L.
5. The method for preparing gel electrolyte according to claim 1, characterized in that, The ionic conductivity of the gel electrolyte is greater than 1.36 × 10⁻⁶. -3 The S / cm ratio is 0.83, the ion transference number is 0.83, and the electrochemical stability window is greater than 4.8V.
6. The method for preparing gel electrolyte according to claim 1, characterized in that, The drying conditions are: a drying temperature of 60-80℃ and a drying time of 1-2 hours; and a stirring temperature of 50-60℃ and a stirring time of 12-15 hours.
7. A lithium-ion battery, characterized in that, The lithium-ion battery includes a gel electrolyte prepared by any one of claims 1 to 6, wherein the lithium-ion battery has an initial charge / discharge capacity greater than 140 mAh / g at 0.1C, a capacity retention of greater than or equal to 92.4% after 100 charge / discharge cycles at 0.2C, a charge / discharge efficiency of greater than or equal to 96%, and a charging capacity of greater than or equal to 96.5% after cycling at different rates.