Recently,there has been worldwide enthusiasm in applying lithium metal as an anode material to batteries.Lithium metal battery could triple the specific energy of today's typical electric vehicle (EV) batteries from 170-200 Wh/kg to 500 Wh/kg.In fact,lithium metal has been intensively studied as an anode material since the 1970s due to its high theoretical capacity (3860 mAh/g) and lowest redox potential (-3.040 Vvs.standard hydrogen electrode) [1].However,uncontrollable dendritic Li growth and limited coulombic efficiency during repeated Li deposition/stripping have prevented practical applications.Incidents of fire followed by manufacture recalls diminished the industrial efforts in the early 1990s [2].