Abstract:The fluorinated organic solvent 2,2,3,3-tetrafluoropropyl methacrylate (TFPMA) was introduced as a dual-function additive in the carbonate electrolyte system. The effect of TFPMA on increasing the wettability was investigated, and the performance of the lithium metal battery after adding TFPMA was tested by using AC impedance and constant current charging and discharging. SEM and XPS were used to characterize the surface of the lithium metal electrode after cycling. Experiments show that after adding TFPMA with a mass fraction of 1%, the contact angle between the electrolyte and the diaphragm is reduced from 53.5° to 44°, and the internal resistance is reduced from 6.15 Ω to 1.94 Ω. The current density of Li-LiFePO4 battery is at 5 C. The specific capacity is increased from 66 mA·h/g to 80 mA·h/g, and the constant current cycle at 1 C current density can maintain a cycle efficiency of more than 99% after 100 cycles. TFPMA also promotes the uniform deposition of Li+ and the formation of excellent SEI films, and inhibits lithium dendrites. After adding 1% TFPMA, Li-Cu batteries can be cycled for more than 100 cycles without significant drop in coulombic efficiency. The SEM image of the electrode learned that the surface of the lithium metal negative electrode added with 1% TFPMA electrolyte is more smooth and has less lithium dendrites.