Lithium-sulfur　(Li–S)　system　coupled　with　thin-film　solid　electrolyte　as　a　novel　high-energy　micro-battery　has　enormous　potential　for　complementing　embedded　energy　harvesters　to　enable　the　autonomy　of　the　Internet　of　Things　microdevice.　However,　the　volatility　in　high　vacuum　and　intrinsic　sluggish　kinetics　of　S　hinder　researchers　from　empirically　integrating　it　into　all-solid-state　thin-film　batteries,　leading　to　inexperience　in　fabricating　all-solid-state　thin-film　Li–S　batteries　(TFLSBs).　Herein,　for　the　first　time,　TFLSBs　have　been　successfully　constructed　by　stacking　vertical　graphene　nanosheets-Li2S　(VGs-Li2S)　composite　thin-film　cathode,　lithium-phosphorous-oxynitride　(LiPON)　thin-film　solid　electrolyte,　and　Li　metal　anode.　Fundamentally　eliminating　Li-polysulfide　shuttle　effect　and　maintaining　a　stable　VGs-Li2S/LiPON　interface　upon　prolonged　cycles　have　been　well　identified　by　employing　the　solid-state　Li–S　system　with　an　“unlimited　Li”　reservoir,　which　exhibits　excellent　long-term　cycling　stability　with　a　capacity　retention　of　81%　for　3,000　cycles,　and　an　exceptional　high　temperature　tolerance　up　to　60　°C.　More　impressively,　VGs-Li2S-based　TFLSBs　with　evaporated-Li　thin-film　anode　also　demonstrate　outstanding　cycling　performance　over　500　cycles　with　a　high　Coulombic　efficiency　of　99.71%.　Collectively,　this　study　presents　a　new　development　strategy　for　secure　and　high-performance　rechargeable　all-solid-state　thin-film　batteries.　[MediaObject　not　available:　see　fulltext.]　©　2023,　The　Author(s).