Preparation method of flame-retardant polymer electrolyte and polymer battery

Abstract

The invention provides a preparation method of a flame-retardant polymer electrolyte and a polymer battery. The flame-retardant polymer electrolyte is prepared from the following raw materials: a carbonate monomer, a flame retardant, an initiator and a liquid electrolyte. The carbonate monomer is cyclic carbonate containing carbon-carbon double bonds, the flame retardant is a phosphate flame retardant, and the liquid electrolyte comprises lithium hexafluorophosphate and a non-aqueous organic solvent. And the flame retardant accounts for 20-40% of the mass of the liquid electrolyte. According to the invention, the content of the phosphate flame retardant is controlled to be 20-40% of the mass of the liquid electrolyte, and through the microscopic synergistic effect between the phosphate flame retardant and the electrolyte in the content range, the migration ability and the ionic conductivity of ions can be improved, so that the electrochemical performance of the polymer battery is improved.

Description

Technical Field

[0001] The present invention relates to the field of new energy technology, in particular to a polymer electrolyte, and more particularly to a method for preparing a flame-retardant polymer electrolyte and a polymer battery. Background Art

[0002] With the increasing demand for lithium-ion batteries in electric vehicles, renewable energy storage systems, and mobile electronic devices, solid-state lithium-ion battery technology has received increasing attention. Solid-state lithium-ion batteries have become a research hotspot in this field due to their high energy density, superior safety, and long cycle life. Polymer solid electrolytes are widely used in solid-state lithium-ion batteries due to their excellent mechanical flexibility and manufacturing convenience. However, traditional polymer solid electrolytes also face challenges in practical applications, such as poor thermal stability, poor flame retardancy, and low ionic conductivity.

[0003] In recent years, the concept of solid-liquid hybrid electrolytes has gradually emerged. This new type of electrolyte combines the advantages of solid electrolytes and liquid electrolytes, has ionic conductivity comparable to that of liquid electrolytes, high safety of solid electrolytes and good cycle stability. In addition, in order to improve the safety of polymer solid electrolytes, adding flame retardants has become an effective solution. Flame retardants can slow down the burning rate of polymers and reduce the heat release rate, thereby significantly improving the safety of batteries under high temperature and extreme conditions. However, high doses of flame retardants will have some negative effects on the electrolytes. For example, excessive flame retardants will occupy a large number of ion transport channels, significantly reduce the overall ionic conductivity of the electrolyte, and affect the rate performance of the battery. In addition, high concentrations of flame retardants may interfere with the good contact and wettability between the electrolyte and the electrode, increase the electrochemical impedance of the electrode-electrolyte interface, and affect the power output and cycle stability of the battery. Therefore, in general, the amount of flame retardant added to solid electrolytes is generally 2~10wt.% of the polymer monomer. However, low levels of flame retardants cannot effectively solve the problems of poor thermal stability and flame retardancy of polymer solid electrolytes in practical applications, and safety issues still pose hidden dangers. Therefore, how to maintain the polymer battery with better safety performance while also taking into account higher ionic conductivity, so as to maintain the battery with better rate and cycle performance, remains the focus of industry research. Summary of the invention

[0004] Based on the above problems, the purpose of the present invention is to provide a method for preparing a flame retardant polymer electrolyte and a polymer battery, wherein the polymer electrolyte has better flame retardant properties, can ensure the safety performance of the polymer battery, and can greatly improve the ionic conductivity of the polymer electrolyte and the electrochemical stability of the polymer battery.

[0005] To achieve the above-mentioned purpose, the present invention provides a flame-retardant polymer electrolyte on the one hand, wherein the raw materials for preparing the polymer electrolyte include a carbonate monomer, a flame retardant, an initiator and a liquid electrolyte, wherein the carbonate monomer is a cyclic carbonate containing a carbon-carbon double bond, the flame retardant is a phosphate flame retardant, and the liquid electrolyte includes lithium hexafluorophosphate and a non-aqueous organic solvent, and the flame retardant accounts for 20 to 40% of the mass of the liquid electrolyte.

[0006] In the in-situ polymerization process of conventional polymer electrolytes, a crosslinking agent needs to be added to convert linear or slightly branched polymer monomers into a three-dimensional network structure, thereby improving the strength, heat resistance, wear resistance, solvent resistance and other properties of the electrolyte. However, the addition of a crosslinking agent may hinder the migration of lithium ions in the electrolyte, resulting in a decrease in the overall ionic conductivity, which is not conducive to the electrochemical performance of the battery. The raw materials for the preparation of the flame-retardant polymer electrolyte of the present invention do not use a crosslinking agent, which can avoid the negative impact of the crosslinking agent on ion transport and maintain good ionic conductivity and electrochemical properties. This is not only conducive to improving the rate performance and low temperature performance of the battery, but also greatly reduces the cost and process complexity of battery manufacturing because there is no need to add a complex crosslinking agent system. More importantly, although the present invention does not add a crosslinking agent, a high content of phosphate flame retardant can be used to participate in the regulation of the electrolyte structure.

[0007] Specifically, since excessive flame retardants will occupy a large number of ion transmission channels, significantly reduce the overall ionic conductivity of the electrolyte, and increase the electrochemical impedance of the electrode-electrolyte interface, the amount of flame retardants added to solid electrolytes is generally 2-10wt.% of the polymer monomer, so as to balance the flame retardancy and the electrochemical properties of polymer batteries. In the present invention, the inventors found that the content of phosphate flame retardants was controlled to account for 20-40% of the mass of the liquid electrolyte. Through this ratio, phosphate flame retardants and electrolytes can produce synergistic effects, optimizing the conduction path of ions in the electrolyte. High content of phosphate flame retardants can be used as plasticizers to reduce the glass transition temperature of the polymer matrix, improve the flexibility and fluidity of the polymer, and significantly change the microstructure of the electrolyte and the solvation structure of lithium ions in the electrolyte, thereby improving the migration ability of ions in the solvation shell and further optimizing the connectivity of ion transmission channels.

[0008] Therefore, the present invention controls the content of the phosphate flame retardant to 20-40% of the mass of the liquid electrolyte. Through the microscopic synergistic effect between the phosphate flame retardant and the electrolyte within this content range, the mobility of ions and the ionic conductivity can be improved, thereby improving the electrochemical performance of the polymer battery.

[0009] As a technical solution of the present invention, the carbonate monomer includes one or more of vinylene carbonate, vinyl ethylene carbonate, methyl vinylene carbonate, ethyl vinylene carbonate, 1,2-dimethyl vinylene carbonate, 1,2-diethyl vinylene carbonate, fluorovinylene carbonate, trifluoromethyl vinylene carbonate, vinyl ethylene carbonate, 1-methyl-2-vinyl ethylene carbonate, 1-ethyl-2-vinyl ethylene carbonate, 1-n-propyl-2-vinyl ethylene carbonate, 1-methyl-2-vinyl ethylene carbonate, 1,1-divinyl ethylene carbonate, 1,2-divinyl ethylene carbonate, 1,1-dimethyl-2-methylene ethylene carbonate, 1,1-diethyl-2-methylene ethylene carbonate, and ethylene carbonate.

[0010] As a technical solution of the present invention, the carbonate monomer accounts for 20-40% of the sum of the mass of the liquid electrolyte and the flame retardant.

[0011] As a technical solution of the present invention, the flame retardant includes one or more of triethyl phosphate, trimethyl phosphate, triphenyl phosphate, trichloroethyl phosphate, diethyl phosphate and diethyl chlorophosphate.

[0012] As a technical solution of the present invention, the initiator includes one or more of azobisisobutyronitrile, azobisisoheptanenitrile, dibenzoyl peroxide, dodecyl peroxide, di(2-ethylhexyl) peroxydicarbonate and tert-butyl peroxyvalerate.

[0013] As a technical solution of the present invention, the initiator accounts for 0.1-0.5% of the mass of the carbonate monomer.

[0014] As a technical solution of the present invention, the non-aqueous organic solvent includes one or more of ethylene carbonate, propylene carbonate, dimethyl carbonate, ethyl methyl carbonate, diethyl carbonate, fluoroethylene carbonate, ethylene glycol dimethyl ether, 1,2-dimethoxyethane, tetrahydrofuran and 2-methyltetrahydrofuran.

[0015] Another aspect of the present invention provides a method for preparing a polymer battery, which uses the carbonate monomer of the aforementioned flame-retardant polymer electrolyte as a monomer, introduces the liquid electrolyte, the flame retardant and the initiator to obtain a precursor, and then injects it into a battery and allows it to stand for a certain period of time at a certain temperature to obtain a precursor.

[0016] As a technical solution of the present invention, the ratio of the capacity of the battery to the injection amount of the precursor is 2-6 mA / g, the certain temperature is 50-100° C., and the certain time is 4-24 hours.

[0017] As a technical solution of the present invention, the battery includes a positive electrode, a negative electrode and a separator between the positive electrode and the negative electrode. DETAILED DESCRIPTION

[0018] The preparation method of the polymer battery of the present invention comprises taking carbonate monomer as monomer, introducing liquid electrolyte, flame retardant and initiator to obtain precursor, and then injecting into the battery and standing for a certain time at a certain temperature to obtain the precursor.

[0019] The battery includes a positive electrode, a negative electrode and a separator between the positive electrode and the negative electrode. The positive electrode is one of lithium iron phosphate, nickel cobalt manganese ternary material, nickel cobalt aluminum ternary material, lithium cobalt oxide and lithium manganese oxide. The negative electrode is one of graphite, silicon, soft carbon, hard carbon and lithium metal. The separator is one of polyethylene separator, polypropylene separator, polyimide separator, cellulose separator, glass fiber separator, polyethylene terephthalate separator and non-woven separator.

[0020] As a technical solution of the present invention, the ratio of the capacity of the battery to the injection amount of the precursor is 2~6mA / g, preferably 2~4mA / g, as an example, it can be but not limited to 2mA / g, 3mA / g, 4mA / g, 5mA / g, 6mA / g. The certain temperature is 50~100℃, preferably 60~80℃, as an example, it can be but not limited to 50℃, 55℃, 60℃, 65℃, 70℃, 75℃, 80℃, 86℃, 90℃, 95℃, 100℃. The certain time is 4~24h, preferably 8~12h, as an example, it can be but not limited to 4h, 8h, 12h, 14h, 16h, 18h, 20h, 22h, 24h.

[0021] The carbonate monomer is a cyclic carbonate containing a carbon-carbon double bond. Further, the carbonate monomer includes one or more of vinylene carbonate, vinyl ethylene carbonate, methyl vinylene carbonate, ethyl vinylene carbonate, 1,2-dimethyl vinylene carbonate, 1,2-diethyl vinylene carbonate, fluorovinylene carbonate, trifluoromethyl vinylene carbonate, vinyl ethylene carbonate, 1-methyl-2-vinyl ethylene carbonate, 1-ethyl-2-vinyl ethylene carbonate, 1-n-propyl-2-vinyl ethylene carbonate, 1-methyl-2-vinyl ethylene carbonate, 1,1-divinyl ethylene carbonate, 1,2-divinyl ethylene carbonate, 1,1-dimethyl-2-methylene ethylene carbonate, 1,1-diethyl-2-methylene ethylene carbonate, and ethylene carbonate. The carbonate monomer accounts for 20-40% of the mass of the liquid electrolyte. As examples, it can be but is not limited to 20%, 22%, 24%, 26%, 28%, 30%, 32%, 34%, 36%, 38%, and 40%.

[0022] The flame retardant is a phosphate flame retardant, and the flame retardant includes one or more of triethyl phosphate, trimethyl phosphate, triphenyl phosphate, trichloroethyl phosphate, diethyl phosphate and diethyl chlorophosphate. The flame retardant accounts for 20-40% of the mass of the liquid electrolyte, and as an example, it can be but not limited to 20%, 22%, 24%, 26%, 28%, 30%, 32%, 34%, 36%, 38%, 40%.

[0023] The initiator includes one or more of azobisisobutyronitrile, azobisisoheptylnitrile, dibenzoyl peroxide, dodecyl peroxide, di(2-ethylhexyl) peroxydicarbonate, and tert-butyl peroxyvalerate. The initiator accounts for 0.1-0.5% of the mass of the carbonate monomer, and as an example, it can be, but is not limited to, 0.1%, 0.2%, 0.3%, 0.4%, and 0.5%.

[0024] The liquid electrolyte includes lithium hexafluorophosphate and a non-aqueous organic solvent, and the non-aqueous organic solvent includes one or more of ethylene carbonate, propylene carbonate, dimethyl carbonate, ethyl methyl carbonate, diethyl carbonate, fluoroethylene carbonate, ethylene glycol dimethyl ether, 1,2-dimethoxyethane, tetrahydrofuran and 2-methyltetrahydrofuran.

[0025] In order to better illustrate the purpose, technical scheme and beneficial effects of the present invention, the present invention will be further described below in conjunction with specific embodiments. It should be noted that the following implementation method is a further explanation of the present invention and should not be used as a limitation of the present invention.

[0026] Example 1 This embodiment is a flame retardant polymer electrolyte, the raw materials for preparation include vinylene carbonate, triethyl phosphate, azobisisobutyronitrile and liquid electrolyte. The liquid electrolyte includes 1 mol / L lithium hexafluorophosphate and a mixed solvent, and the mixed solvent is vinyl carbonate, ethyl methyl carbonate and diethyl carbonate in a volume ratio of 2:3:1.

[0027] The preparation method of the flame-retardant polymer electrolyte of this embodiment includes: weighing 5.0g of lithium hexafluorophosphate and dissolving it in 15.0g of triethyl phosphate and stirring for 5min to obtain a mixed solution, weighing 2.0g of the mixed solution in a 20ml sample bottle, adding 2.0g of vinylene carbonate and 3.5g of liquid electrolyte to the above sample bottle (so that triethyl phosphate finally accounts for 37.5% of the mass of the liquid electrolyte, and vinylene carbonate accounts for 36.4% of the sum of the mass of the liquid electrolyte and triethyl phosphate), stirring for 30min to obtain a uniform mixed solution. Take 0.005g of azobisisobutyronitrile and add it to the above uniform mixed solution, heat and stir at 60℃ for 1.5h to obtain the raw material for preparing the flame-retardant polymer electrolyte. Example 2 The difference from Example 1 is that the amount of triethyl phosphate is 18.3 g, accounting for 40% of the mass of the liquid electrolyte, and the rest is the same as Example 1.

[0028] Example 3 The difference from Example 1 is that the amount of triethyl phosphate is 12.4 g, accounting for 35% of the mass of the liquid electrolyte, and the rest is the same as Example 1.

[0029] Example 4 The difference from Example 1 is that the amount of triethyl phosphate is 8.7 g, accounting for 30% of the mass of the liquid electrolyte, and the rest is the same as Example 1.

[0030] Example 5 The difference from Example 1 is that the amount of triethyl phosphate is 6.1 g, accounting for 25% of the mass of the liquid electrolyte, and the rest is the same as Example 1.

[0031] Example 6 The difference from Example 1 is that the amount of triethyl phosphate is 4.2 g, accounting for 20% of the mass of the liquid electrolyte, and the rest is the same as Example 1.

[0032] Example 7 The difference from Example 1 is that the amount of vinylene carbonate is 0.28 g, accounting for 5% of the total mass of the liquid electrolyte and triethyl phosphate. The rest is the same as Example 1.

[0033] Example 8 The difference from Example 1 is that the amount of vinylene carbonate is 0.55 g, accounting for 10% of the total mass of the liquid electrolyte and triethyl phosphate. The rest is the same as Example 1.

[0034] Example 9 The difference from Example 1 is that the amount of vinylene carbonate is 0.82 g, accounting for 15% of the total mass of the liquid electrolyte and triethyl phosphate. The rest is the same as Example 1.

[0035] Example 10 The difference from Example 1 is that the amount of vinylene carbonate is 1.10 g, accounting for 20% of the sum of the mass of the liquid electrolyte and triethyl phosphate. The rest is the same as Example 1.

[0036] Embodiment 11 The difference from Example 1 is that the amount of vinylene carbonate is 1.65 g, accounting for 30% of the sum of the mass of the liquid electrolyte and triethyl phosphate. The rest is the same as Example 1.

[0037] Example 12 The difference from Example 1 is that the amount of vinylene carbonate is 2.20 g, accounting for 40% of the sum of the mass of the liquid electrolyte and triethyl phosphate. The rest is the same as Example 1.

[0038] Example 13 The difference from Example 1 is that the amount of vinylene carbonate is 2.75 g, accounting for 50% of the sum of the mass of the liquid electrolyte and triethyl phosphate. The rest is the same as Example 1.

[0039] Embodiment 14 The difference from Example 1 is that the amount of vinylene carbonate is 3.30 g, accounting for 60% of the sum of the mass of the liquid electrolyte and triethyl phosphate. The rest is the same as Example 1.

[0040] Embodiment 15 The difference from Example 1 is that the amount of vinylene carbonate is 3.85 g, accounting for 70% of the sum of the mass of the liquid electrolyte and triethyl phosphate. The rest is the same as Example 1.

[0041] Example 16 The difference from Example 1 is that the amount of vinylene carbonate is 4.40 g, accounting for 80% of the sum of the mass of the liquid electrolyte and triethyl phosphate. The rest is the same as Example 1.

[0042] Embodiment 17 This embodiment is a flame retardant polymer electrolyte, the raw materials for preparation include ethylene carbonate, triphenyl phosphate, dibenzoyl peroxide and liquid electrolyte. The liquid electrolyte includes 1 mol / L lithium hexafluorophosphate and a mixed solvent, and the mixed solvent is propylene carbonate and diethyl carbonate in a volume ratio of 1:1.

[0043] The preparation method of the flame-retardant polymer electrolyte of this embodiment includes: weighing 15.0g of lithium hexafluorophosphate and dissolving it in 15.0g of triphenyl phosphate and stirring for 5min to obtain a mixed solution, weighing 3.0g of the mixed solution in a 20ml sample bottle, adding 2.0g of vinyl ethylene carbonate and 2.5g of liquid electrolyte to the above sample bottle (so that triphenyl phosphate finally accounts for 37.5% of the mass of the liquid electrolyte, and vinyl ethylene carbonate accounts for 36.4% of the sum of the mass of the liquid electrolyte and triphenyl phosphate), stirring for 30min to obtain a uniform mixed solution. Take 0.008g of dibenzoyl peroxide and add it to the above uniform mixed solution, heat and stir at 60℃ for 1.5h to obtain the raw material for preparing the flame-retardant polymer electrolyte. Comparative Example 1 The difference from Example 1 is that 17.5 g of triethyl phosphate is weighed into a 100 ml sample bottle, 7.64 g of vinylene carbonate and 3.5 g of liquid electrolyte are added to the sample bottle (so that triethyl phosphate finally accounts for 500% of the mass of the liquid electrolyte, and vinylene carbonate accounts for 36.4% of the sum of the mass of the liquid electrolyte and triethyl phosphate), and a uniform mixed solution is obtained after stirring for 30 minutes. The rest is the same as Example 1.

[0044] Comparative Example 2 The difference from Example 1 is that 7.0 g of triethyl phosphate is weighed into a 100 ml sample bottle, 3.82 g of vinylene carbonate and 3.5 g of liquid electrolyte are added into the sample bottle (so that triethyl phosphate finally accounts for 200% of the mass of the liquid electrolyte, and vinylene carbonate accounts for 36.4% of the sum of the mass of the liquid electrolyte and triethyl phosphate), and a uniform mixed solution is obtained after stirring for 30 minutes. The rest is the same as Example 1.

[0045] Comparative Example 3 The difference from Example 1 is that 4.9 g of triethyl phosphate is weighed into a 100 ml sample bottle, 3.06 g of vinylene carbonate and 3.5 g of liquid electrolyte are added to the sample bottle (so that triethyl phosphate finally accounts for 140% of the mass of the liquid electrolyte, and vinylene carbonate accounts for 36.4% of the sum of the mass of the liquid electrolyte and triethyl phosphate), and a uniform mixed solution is obtained after stirring for 30 minutes. The rest is the same as Example 1.

[0046] Comparative Example 4 The difference from Example 1 is that 3.5 g of triethyl phosphate is weighed into a 100 ml sample bottle, 2.55 g of vinylene carbonate and 3.5 g of liquid electrolyte are added to the sample bottle (so that triethyl phosphate finally accounts for 100% of the mass of the liquid electrolyte, and vinylene carbonate accounts for 36.4% of the sum of the mass of the liquid electrolyte and triethyl phosphate), and a uniform mixed solution is obtained after stirring for 30 minutes. The rest is the same as Example 1.

[0047] Comparative Example 5 The difference from Example 1 is that 2.45 g of triethyl phosphate is weighed into a 100 ml sample bottle, 2.17 g of vinylene carbonate and 3.5 g of liquid electrolyte are added to the sample bottle (so that triethyl phosphate finally accounts for 70% of the mass of the liquid electrolyte, and vinylene carbonate accounts for 36.4% of the sum of the mass of the liquid electrolyte and triethyl phosphate), and a uniform mixed solution is obtained after stirring for 30 minutes. The rest is the same as Example 1.

[0048] Comparative Example 6 The difference from Example 1 is that 1.75 g of triethyl phosphate is weighed into a 100 ml sample bottle, 1.91 g of vinylene carbonate and 3.5 g of liquid electrolyte are added to the sample bottle (so that triethyl phosphate finally accounts for 50% of the mass of the liquid electrolyte, and vinylene carbonate accounts for 36.4% of the sum of the mass of the liquid electrolyte and triethyl phosphate), and a uniform mixed solution is obtained after stirring for 30 minutes. The rest is the same as Example 1.

[0049] Comparative Example 7 The difference from Example 1 is that 1.58 g of triethyl phosphate is weighed into a 100 ml sample bottle, 1.85 g of vinylene carbonate and 3.5 g of liquid electrolyte are added to the sample bottle (so that triethyl phosphate finally accounts for 45% of the mass of the liquid electrolyte, and vinylene carbonate accounts for 36.4% of the sum of the mass of the liquid electrolyte and triethyl phosphate), and a uniform mixed solution is obtained after stirring for 30 minutes. The rest is the same as Example 1.

[0050] Comparative Example 8 The difference from Example 1 is that the amount of triethyl phosphate is 2.80 g, accounting for 15% of the mass of the liquid electrolyte, and the rest is the same as Example 1.

[0051] Comparative Example 9 The difference from Example 1 is that the amount of triethyl phosphate is 1.67 g, accounting for 10% of the mass of the liquid electrolyte, and the rest is the same as Example 1.

[0052] Comparative Example 10 The difference from Example 1 is that the amount of triethyl phosphate is 0.75 g, accounting for 5% of the mass of the liquid electrolyte, and the rest is the same as Example 1.

[0053] The negative electrode sheet was made of lithium metal, the positive electrode sheet was made of LiCO2, 60 μL of the raw materials for preparing the flame-retardant polymer electrolyte of Examples 1 to 17 and Comparative Examples 1 to 10 were taken and transferred to the polypropylene separator, and the button battery was assembled in the order of the negative electrode shell, the negative electrode sheet, the polypropylene separator, the positive electrode sheet, the stainless steel gasket, the spring sheet, and the positive electrode shell. After the battery was left at room temperature for 24 hours, it was left at 60°C for 12 hours to obtain a polymer battery.

[0054] By obtaining the AC impedance diagram of the polymer battery prepared from the raw materials for preparing the flame-retardant polymer electrolyte of Examples 1 to 17 and Comparative Examples 1 to 10 at room temperature, the corresponding ionic conductivity is obtained. By obtaining the linear sweep voltammogram of the polymer battery prepared from the raw materials for preparing the flame-retardant polymer electrolyte of Examples 1 to 17 and Comparative Examples 1 to 10 at room temperature, the electrochemical window data is obtained. By obtaining the polarization curve diagram of the polymer battery prepared from the raw materials for preparing the flame-retardant polymer electrolyte of Examples 1 to 17 and Comparative Examples 1 to 10 at room temperature and the corresponding AC impedance spectrum before and after polarization, the lithium ion migration number is obtained. The flame retardant performance of the polymer battery prepared from the raw materials for preparing the flame-retardant polymer electrolyte of Examples 1 to 17 and Comparative Examples 1 to 10 is tested to obtain the corresponding flame retardancy grade. The corresponding test results are shown in Table 1.

[0055] It can be seen from the results in Table 1 that the present application does not need to add a cross-linking agent and controls the phosphate flame retardant to a certain high content. Through the microscopic synergistic effect between the phosphate flame retardant and the electrolyte within a high content range, while having high flame retardant properties, it can also improve the ion mobility and ion conductivity, thereby improving the electrochemical properties of the polymer battery.

[0056] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit the protection scope of the present invention. Although the present invention is described in detail with reference to the preferred embodiments, it is not limited to the embodiments. Those skilled in the art should understand that the technical solutions of the present invention can be applied to The scheme can be modified or replaced by equivalents without departing from the essence and scope of the technical solution of the present invention.

[0057] Table 1 Performance test results of various embodiments and comparative examples

Claims

1. A flame retardant polymer electrolyte, characterized in that: The preparation raw materials include carbonate monomer, flame retardant, initiator and liquid electrolyte, the carbonate monomer is a cyclic carbonate containing carbon-carbon double bonds, the flame retardant is a phosphate flame retardant, the liquid electrolyte includes lithium hexafluorophosphate and a non-aqueous organic solvent, and the flame retardant accounts for 20-40% of the mass of the liquid electrolyte.

2. The flame retardant polymer electrolyte according to claim 1, characterized in that: The carbonate monomer includes one or more of vinylene carbonate, vinyl ethylene carbonate, methyl vinylene carbonate, ethyl vinylene carbonate, 1,2-dimethyl vinylene carbonate, 1,2-diethyl vinylene carbonate, fluorovinylene carbonate, trifluoromethyl vinylene carbonate, vinyl ethylene carbonate, 1-methyl-2-vinyl ethylene carbonate, 1-ethyl-2-vinyl ethylene carbonate, 1-n-propyl-2-vinyl ethylene carbonate, 1-methyl-2-vinyl ethylene carbonate, 1,1-divinyl ethylene carbonate, 1,2-divinyl ethylene carbonate, 1,1-dimethyl-2-methylene ethylene carbonate, 1,1-diethyl-2-methylene ethylene carbonate, and ethylene ethylene carbonate.

3. The flame retardant polymer electrolyte according to claim 1, characterized in that: The carbonate monomer accounts for 20-40% of the sum of the mass of the liquid electrolyte and the flame retardant.

4. The flame retardant polymer electrolyte according to claim 1, characterized in that: The flame retardant includes one or more of triethyl phosphate, trimethyl phosphate, triphenyl phosphate, trichloroethyl phosphate, diethyl phosphate and diethyl chlorophosphate.

5. The flame retardant polymer electrolyte according to claim 1, characterized in that: The initiator includes one or more of azobisisobutyronitrile, azobisisoheptanenitrile, dibenzoyl peroxide, dodecanoyl peroxide, di(2-ethylhexyl) peroxydicarbonate and tert-butyl peroxyvalerate.

6. The flame retardant polymer electrolyte according to claim 1, characterized in that: The initiator accounts for 0.1-0.5% of the mass of the carbonate monomer.

7. The flame retardant polymer electrolyte according to claim 1, characterized in that: The non-aqueous organic solvent includes one or more of ethylene carbonate, propylene carbonate, dimethyl carbonate, ethyl methyl carbonate, diethyl carbonate, fluoroethylene carbonate, ethylene glycol dimethyl ether, 1,2-dimethoxyethane, tetrahydrofuran and 2-methyltetrahydrofuran.

8. A method for preparing a polymer battery, characterized in that: The flame retardant polymer electrolyte described in any one of claims 1 to 7 is prepared by using the carbonate monomer as a monomer, introducing the liquid electrolyte, the flame retardant and the initiator to obtain a precursor, and then injecting it into a battery and standing it for a certain time at a certain temperature.

9. The method for preparing a polymer battery according to claim 8, characterized in that: The ratio of the capacity of the battery to the injection amount of the precursor is 2-6 mA / g, the certain temperature is 50-100° C., and the certain time is 4-24 hours.

10. The method for preparing a polymer battery according to claim 8, characterized in that: The battery includes a positive electrode, a negative electrode, and a separator interposed between the positive electrode and the negative electrode.

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