Electrolyte solvation chemistry to construct an anion-tuned interphase for stable high-temperature lithium metal batteries

Lithium metal batteries are regarded as promising alternative next-generation energy storage systems.However,the unstable anode interphase results in dendrite growth and irreversible lithium consumption with low Coulombic efficiency(CE).Herein,we rationally design a Li^(+)coordination structure via electrolyte solvation chemistry.Nitrate anions are aggregated in the solvation sheath,even at low concentration in a solvent with moderate solvation ability,which promotes Li^(+)desolvation and constructs a nitrate anion-tuned interphase.Meanwhile,a high-donor-number solvent is introduced as an additive to strongly coordinate with Li^(+),which accelerates the ion-transfer kinetics and rate performance.This not only results in micro-sized lithium deposition and a high CE of 99.5%over 3500 h,but also enables superior anode stability even under 50%depth plating/stripping and with a lean electrolyte of 3 g Ah^(-1)at 50℃.A lithium-sulfur battery exhibits a prolonged lifespan of 2000 cycles with an average CE of 100%.A full battery using 1x excess lithium exhibits a high capacity near 1600 mAh g S^(-1)for 100 cycles without capacity loss.Moreover,a 0.55 Ah pouch cell delivers a reversible energy density of 423 Wh kg^(-1)based on these electrodes and electrolyte.