Improved Cycling Stability of Lithium-Metal Anode with Concentrated Electrolytes Based on Lithium (Fluorosulfonyl)(trifluoromethanesulfonyl)imide

A new type of concentrated electrolyte composed of Li[(FSO₂)N(SO₂CF₃)] (LiFTFSI), Li[N(SO₂F)₂] (LiFSI), and ether solvents can improve the cycling stability of lithium (Li) metal and inhibit Li-metal dendritic growth. The high average coulombic efficiency of >95% and excellent cycling performance of >250 cycles for the Li|copper cells have been achieved, even at a high current density of 3mAcm^-2. Moreover, the Li|LiFePO₄ cell exhibits superior cycling stability with capacity retention of >92% at 0.2C for more than 200 cycles and excellent C-rate capability. Exhibitionist! A concentrated electrolyte based on a salt of LiFTFSI for application in rechargeable Li batteries can improve the cycling stability of Li metal and inhibit Li-metal dendritic growth. The Li|Cu cell displays a high average coulombic efficiency and excellent cycling performance, even at a high current density. Moreover, the Li|LiFePO₄ cell exhibits superior cycling stability with capacity retention of >92% at 0.2C for more than 200 cycles and excellent rate capability.