Design of corrosion resistant Ce-enhanced hybrid solid electrolyte interphase by Ce(TFSI)3 additives for lithium metal batteries

Lithium (Li) metal is the ideal anode material for building future large-scale energy storage batteries. Nevertheless, Li metal anodes suffer from incompatibility with conventional carbonate-based electrolytes, which possibly leads to severe Li dendrite growth, undesirable electrolyte decomposition, and rapid deterioration of the cycling performance. To address these challenges, the traditional commercial electrolyte is doped with cerium bis(trifluoromethanesulfonyl)imide (Ce(TFSI) 3 ) for enhanced Li anode stability. The low migration rate of Ce 3+ leads to formation of a Ce-enriched corrosion resistant solid electrolyte interphase (SEI), while the TFSI − anion enables a significant enhancement of inorganic components within the SEI, thus facilitating uniform Li + deposition and mitigation of detrimental electrolyte decomposition. The resulting electrolyte exhibits superior electrochemical stability against Li anodes. This is evidenced by a Li||Li symmetric cell that cycles steadily for over 1300 h at a current density of 1 mA cm −2 and a capacity of 1 mAh cm −2 , along with a exchange current density of 1.3183 mA cm −2 . Additionally, Li||LiFePO 4 full cell demonstrates 76.8% capacity retention (110.39 mA cm −2 ) after 900 cycles at 1 C. This work illustrates the significant impact of a corrosion-resistant interface on Li anode performance and offers a valuable idea for constructing high-durability SEI layers.