| Lithium-ion batteries(LIBs)have been so successful in powering modern society's portable electronic devices that in the near future they will be used in modern transportation electrification and wind or solar storage in smart grids.However,the safety of lithium-ion batteries based on organic liquid electrolytes,which are widely used at present,is becoming more and more serious because of their volatile and flammable properties.This has led to the exploration and development of solid electrolytes to improve the safety of the next generation of high-energy LIBs.However,the interface between most solid electrolyte and electrode material is solid-solid state,so the effective contact between electrode and electrolyte is weak,and the ion transport kinetics in solid material is low,resulting in low ionic conductivity.In this paper,we describe two inorganic-organic hybrid solid electrolyte systems for lithium-ion batteries.Solvated ionic liquid-based inorganic packing composite solid electrolyte and solvated ionic liquid-based two-dimensional inorganic packing composite solid electrolyte were designed and prepared emphatically.The content of solvated ionic liquid in electrolyte,the influence of the type of ionic liquid and inorganic filler on the electrolyte state,thermal stability,electrochemical performance and battery performance were studied.The experimental results show that the designed electrolyte has the advantages of high safety performance and superior electrochemical performance.The main research contents are as following:(1)In this paper,the molar mixture[Li(G4)X][TFSI],also known as solvated ionic liquid(SILS),is prepared with ZSM-5 molecular sieve to prepare quasi solid electrolyte,referred to as SILs@ZSM-5.The electrochemical properties of electrolytes prepared by solvated ionic liquids at different concentrations of lithium salts were investigated,and the electrochemical properties of the electrolytes when applied to lithium ion batteries were investigated.The results show that the high concentration of solvated ionic liquid(SILs)has a high viscosity.After appropriate optimization of molar ratio,when LiTFSI:G4 is 1:3 solvation ionic liquid[Li(G4)3][TFSI]preparation of electrolyte electrochemical window is 5.29 V,lithium migration value of 0.30,ionic conductivity at room temperature is 9.45×10-4 S/cm,the first charge and discharge specific capacity of 122 m Ah/g,charge and discharge specific capacity after 1000 laps in a 81 m Ah/g,compared with the initial discharge specific capacity can keep 66%.(2)In this paper,the molar mixture[Li(G4)X][TFSI]of bis(trifluoromethyl sulfonic acid)lithium-iminimide(LiTFSI)and tetraethylene glycol dimethyl ether(G4)was prepared by designing experiments,and the quasi-solid electrolyte was prepared by hydrosliding Mg-Al LDHs with magnesium and aluminum,SILs@Mg-Al LDHs for short.The electrochemical properties of the electrolytes prepared by solvated ionic liquids at different concentrations of lithium salts were investigated,and the electrochemical properties of electrolytes when applied to lithium ion batteries were investigated.The results show that the high concentration of solvated ionic liquid(SILs)has a high viscosity.After appropriate optimization of molar ratio,when LiTFSI:G4 is 1:2 solvation as ionic liquid[Li(G4)2][TFSI]preparation of electrolyte electrochemical window is 5.30 V,lithium migration value of 0.34,ionic conductivity at room temperature is 7.99×10-4 S/cm,the first charge and discharge specific capacity of 152 m Ah/g,charge and discharge specific capacity after 1560laps in a 108 m Ah/g,compared with the initial discharge specific capacity can keep 71%. |
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