Lithium‑sulfur　(Li[sbnd]S)　batteries　have　attracted　tremendous　attentions　as　promising　energy　storage　systems　because　of　their　remarkable　energy　density　and　the　affordability　of　sulfur.　Unfortunately,　the　commercialization　of　Li[sbnd]S　batteries　still　suffer　from　major　obstacles　such　as　the　sluggish　redox　reaction　kinetics　and　the　shuttle　effect　of　soluble　lithium　polysulfides　(LiPSs).　Herein,　a　heterostructure　electrocatalyst　consisting　of　p-block　bismuth　(Bi)　metal　and　oxygen　vacancy　enriched　vanadium　oxide　(V2O3-x)　that　concatenated　by　electrospun　carbon　nanofibers　(CNF@Bi/V2O3-x)　has　been　rationally　designed　as　a　free-standing　multifunctional　interlayer　to　bidirectionally　catalyze　the　sulfur　redox　reactions,　thereby　improving　the　sulfur　utilization　and　suppressing　the　shuttle　effect.　Meanwhile,　the　CNF@Bi/V2O3-x　interlayer　modulates　the　distribution　of　lithium　ion　flux,　thus　mitigating　the　dendrite　formation　at　the　anode　region.　Furthermore,　combined　theoretical　calculations　and　experimental　results　reveal　that　the　heterostructure　design　and　vacancy　engineering　significantly　facilitate　the　electron　transfer,　regulate　the　absorption　ability　and　boost　the　bidirectional　conversion　of　LiPSs.　Consequently,　Li[sbnd]S　batteries　assembled　with　the　CNF@Bi/V2O3-x　interlayers　achieve　high　specific　discharge　capacities,　outstanding　rate　performance,　decent　long-term　cycling　stability　and　high　sulfur　utilization　even　under　high　sulfur　loading　and　lean　electrolyte　conditions.　More　encouragingly,　a　flexible　Li[sbnd]S　pouch　cell　is　also　fabricated　and　delivers　satisfactory　performance,　further　confirming　the　great　potential　of　the　CNF@Bi/V2O3-x　interlayers　for　practical　applications.　This　contribution　not　only　underscores　the　importance　of　heterostructure　design　and　vacancy　engineering　in　interlayer　materials,　but　also　provides　valuable　insights　for　bidirectionally　accelerating　the　polysulfide　conversion　for　high-performance　Li[sbnd]S　batteries.　©　2025　Elsevier　B.V.