Lithium　metals　have　been　considered　as　the　most　promising　anode　materials　for　next-generation　rechargeable　batteries　due　to　their　high　theoretical　capacity　and　low　potential.　Unfortunately,　lithium　metal　anodes　(LMAs)　usually　suffer　from　immoderate　dendrite　growth　during　the　cycling　process,　which　can　cause　serious　safety　concerns.　Herein,　we　develop　an　alloy/polymer　double-layered　protective　coating　as　an　artificial　solid　electrolyte　interphase　(SEI)　to　mitigate　the　above　problem.　The　inorganic　alloy　(LiF-rich　Li-Sb)　layer　is　lithiophilic　with　high　Li-ion　conductivity,　enabling　dendrite-free　plating/stripping　of　lithium　at　a　high　capacity.　The　organic　polymer　(commercial　rubber)　layer　is　highly　flexible,　keeping　the　artificial　SEI　stable　during　cycling.　The　use　of　double-layered　coating　results　in　significantly　improved　cycling　stability　for　LMAs　(500　h　for　a　symmetric　cell　with　a　capacity　of　1　mA　h　cm(-2))　in　both　ether-　and　carbonate-based　electrolytes,　which　is　much　better　than　for　cells　employing　pristine　lithium　or　single-alloy-protected　lithium.　It　should　be　noted　that　the　Li-Sb　alloy　layer　was　created　from　a　low-cost　precursor　(SbF3).　We　believe　that　the　design　of　double　layer　protective　coating　using　low-cost　raw　materials　provides　a　new　pathway　to　achieve　dendrite-free　LMAs　with　an　enhanced　cycling　life.