Uniform lithium deposition induced by copper phthalocyanine additive for durable lithium anode in lithium-sulfur batteries

Copper phthalocyanine(CuPc)is adopted as an electrolyte additive to stabilize lithium anode for lithiumsulfur(Li-S)batteries.CuPc with a planar molecular structure and lithiophilic N-containing group,is likely to be adsorbed on the surface of Li anode to form a coating layer,which can restrict the direct contact between Li anode and solvents,and guide the uniform deposition of Li^(+)ions.The Li||Li symmetric cells demonstrate a stable cycle performance,and Li||Cu cells show high Coulombic efficiencies.In Li-S batteries,the formed stable solid-electrolyte interface(SEI)film containing copper sulfides can protect Li anode from the polysulfide corrosion and side reactions with the electrolyte,leading to the compact and smooth surface morphology of Li anode.Therefore,the Li-S batteries with CuPc additive deliver much higher capacity,better cycle performance and rate capability as compared to the one without CuPc additive.