A compact inorganic layer for robust anode protection in lithium-sulfur batteries

Lithium-sulfur(Li-S)batteries are one of the most promising candidates for high energy density rechargeable batteries beyond current Li-ion batteries.However,severe corrosion of Li metal anode and low Coulombic efficiency(CE)induced by the unremitting shuttle of Li polysulfides immensely hinder the practical applications of Li-S batteries.Herein,a compact inorganic layer(CIL)formed by ex situ reactions between Li anode and ionic liquid emerged as an effective strategy to block Li polysulfides and suppress shuttle effect.A CE of 96.7%was achieved in Li-S batteries with CIL protected Li anode in contrast to 82.4%for bare Li anode while no lithium nitrate was employed.Furthermore,the corrosion of Li during cycling was effectively inhibited.While applied to working batteries,80.6%of the initial capacity after 100 cycles was retained in Li-S batteries with CIL-protected ultrathin(33μm)Li anode compared with 58.5%for bare Li anode,further demonstrating the potential of this strategy for practical applications.This study presents a feasible interfacial regulation strategy to protect Li anode with the presence of Li polysulfides and opens avenues for Li anode protection in Li-S batteries under practical conditions.