3D composite lithium metal with multilevel micro-nano structure combined with surface modification for stable lithium metal anodes

Abstract

Lithium (Li) metal has extremely high theoretical specific capacity and low redox potential, which can greatly improve energy density of Li battery. Nevertheless, some troubles including Li dendrite, parasitic reaction and volumetric change extremely restrict its practical application. Herein, a strategy of combining 3D composite lithium metal and surface modification is proposed for solving these issues simultaneously. The 3D composite lithium metal electrode is synthesized by infusing molten Li into Cu foam, and multilevel micro-nano structure is obtained by alloying reaction between Li and surface part of Cu foam, which can be used as three-dimensional (3D) scaffold with high specific surface area. The surface modification of coating zinc fluoride (ZnF2) is used as artificial solid electrolyte interphase (SEI). The symmetric cell using modified composite Li anode exhibits stable electrochemical performance and long cycling lifespan. And the excellent performance of LiCoO2 (LCO) cell (average 121 mAh g−1) is achieved, compared to pristine Li of 114 mAh g−1.