Adjusting Interfacial Reactions for Achieving Highly Stable Operation in Lithium Metal Batteries

Lithium-metal batteries (LMBs) are considered a promisingcandidatefor next-generation high energy-density batteries. However, the unstableinterface and dendrite growth severely restrict the commercial applicationsof lithium metal anodes. Here, we pioneeringly propose an electrolytethat consists of a simple cyclic vinylethylene carbonate (VEC) solventand LiTFSI salt, enabling LMBs with high performance in the aspectsof long cycle life and high Coulombic efficiency (CE). Jointed experimentaland DFT calculations demonstrate that the favorable reduction of theVEC induces a uniform distribution of elastic organic polymer moleculesat the anode surface with high mechanical strength, which reinforcesthe inorganic Li2CO3 and LiF underneath andmaintains the integrality of the solid electrolyte interphase (SEI)film. The inorganic compounds display a high Li ion diffusion coefficient,surface energy, and Young's modulus (10.71 GPa), which effectivelyaccelerate the interfacial kinetics and homogenize the metallic Lideposition. In addition, the low solvation energy of the Li ions inthe VEC effectively improves the desolvation process compared to traditionalelectrolytes. Thus, this organic/inorganic laminated SEI film enablesan excellent CE of 98% after 450 cycles and highly stable cyclingover 3000 h. This work provides a cost-effective proposal, pavingthe way for industrial applications of cyclic carbonate-based electrolytesin LMBs. The development of LMBs withhigh energy and long livescan decrease the reliance on fossil resources and contribute to sustainabledevelopment.