Construction　of　high　efficiency　and　stable　Li　metal　anodes　is　extremely　vital　to　the　breakthrough　of　Li　metal　batteries.　In　this　study,　for　the　first　time,　groundbreaking　in　situ　plasma　interphase　engineering　is　reported　to　construct　high-quality　lithium　halides-dominated　solid　electrolyte　interphase　layer　on　Li　metal　to　stabilize　&　protect　the　anode.　Typically,　SF6　plasma-induced　sulfured　and　fluorinated　interphase　(SFI)　is　composed　of　LiF　and　Li2S,　interwoven　with　each　other　to　form　a　consecutive　solid　electrolyte　interphase.　Simultaneously,　brand-new　vertical　Co　fibers　(diameter:　approximate　to　5　mu　m)　scaffold　is　designed　via　a　facile　magnetic-field-assisted　hydrothermal　method　to　collaborate　with　plasma-enhanced　Li　metal　anodes　(SFI@Li/Co).　The　Co　fibers　scaffold　accommodates　active　Li　with　mechanical　integrity　and　decreases　local　current　density　with　good　lithiophilicity　and　low　geometric　tortuosity,　supported　by　DFT　calculations　and　COMSOL　Multiphysics　simulation.　Consequently,　the　assembled　symmetric　cells　with　SFI@Li/Co　anodes　exhibit　superior　stability　over　525　h　with　a　small　voltage　hysteresis　(125　mV　at　5　mA　cm(-2))　and　improved　Coulombic　efficiency　(99.7%),　much　better　than　the　counterparts.　Enhanced　electrochemical　performance　is　also　demonstrated　in　full　cells　with　commercial　cathodes　and　SFI@Li/Co　anode.　The　research　offers　a　new　route　to　develop　advanced　alkali　metal　anodes　for　energy　storage.