Polyether　electrolytes　with　high　Li+　conductivity　and　excellent　interfacial　contact　have　garnered　significant　attention.　Yet　further　applications　of　such　electrolytes　in　high-voltage　lithium　metal　batteries　are　severely　hindered　by　the　instability　of　the　electrolyte　and　electrolyte/electrodes　interphases.　Here,　we　report　a　novel　high-voltage　polyether　electrolyte　with　a　“rigid　exterior,　soft　interior”　design,　which　involves　a　3D　F-contained　network　as　a　rigid　exterior　framework,　and　a　unique　solvation　structure　with　intensified　Li+-anion　coordination　as　a　soft　interior　within　the　framework.　The　achieved　electrolyte　demonstrates　an　ionic　conductivity　of　1.13　mS　cm−1　at　25　°C,　a　Li+　transference　number　of　0.85,　and　an　extended　electrochemical　stability　window　of　over　5 V.　Besides,　such　a　designed　polyether　electrolyte　further　induces　salt-philic,　solvent-phobic　interfacial　films　for　stabilizing　electrolyte/electrode　interphases.　An　exceptional　cyclability　in　a　Li||Li　cell　for　over　4000 h,　and　a　preferable　capacity　and　cyclability　in　even　4.6 V　Li||LiNi0.8Co0.1Mn0.1O2　(NCM811)　quasi-solid-state　batteries　(QSSBs)　are　demonstrated.　Meanwhile,　the　resulting　4.3 V　Li||LiNi0.5Co0.2Mn0.3O2　QSSB　shows　a　Coulombic　efficiency　of　∼100%　and　an　extremely　high　capacity　retention　of　95.4%　after　600　cycles　at　3C.　A　capacity　retention　of　over　96.3%　after　400　cycles　at　1C　are　further　realized　in　4.5 V　Li||NCM811　QSSB.　©　2025　Wiley-VCH　GmbH.