Application of LiFSI-LiPF6 Electrolyte in High-grade Nickel/Silicon Carbon Lithium Batteries
The high-grade nickel/silicon carbon system is the most promising next-generation high-energy density lithium-ion battery system.However,owing to weak cycling stability of the battery,its large-scale application is currently limited.It believes in the study that building a stable SEI is one of the key methods to improve the capacity retention rate of high-grade nickel/silicon carbon batteries.LiPF6 in traditional electrolytes produces acidic corrosive products,which are not conducive to the stability of SEI.LiFSI has been proven to have excellent thermal stability and film-forming properties as a novel lithium salt,but it can corrode the positive current collector.The paper makes a study of the application of LiFSI-LiPF6 double-salt electrolyte in high-grade nickel/silicon carbon pouch batteries,and analyzes its electrochemical performance by formation,cycling,and storage tests.The results show that LiFSI-LiPF6 electrolyte can reduce the gas production and internal resistance of battery formation,and enhance electrode stability.The 0.6 mol/dm3 LiFSI+0.6 mol/dm3 LiPF6 battery has the highest capacity retention rate of 75.66％after 1 000 cycles,and its storage voltage drop is 37.64％less than that of the LiFSI single-salt battery.
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