GO/PVP modified solid polymer electrolyte with fast lithium-ion transport for stable and dendrite-free lithium metal batteries

Poly(ethylene oxide) (PEO)-based solid polymer electrolytes (SPEs) are highly attractive for lithium metal batteries, yet their practical viability is fundamentally plagued by sluggish Li + transport, heterogeneous Li deposition, and the severe agglomeration of nanofillers. Herein, we propose a facile “dual-filler synergistic” strategy to architect high-performance SPEs by simultaneously integrating graphene oxide (GO) nanosheets and non-ionic polyvinylpyrrolidone (PVP) into the PEO-LiTFSI matrix. The hydrophobic groups of PVP are anchored onto GO surfaces to construct a polymeric steric layer, synergistically suppressing PEO crystallinity and accelerating lithium salt dissociation. Benefiting from the dual modulation, the GO/PVP-modified PEO electrolyte (GPP SPE) exhibits an ionic conductivity of 4.1 × 10 −4 S cm −1 and a Li + transference number of 0.57 at 60 o C, coupled with a broadened electrochemical stability window of 4.75 V. Consequently, GPP SPE exhibits superior dendrite suppression, enabling symmetric Li||Li cell to cycle stably for over 1000 h at 0.1 mA cm −2 without short-circuiting. Furthermore, the assembled LiFePO 4 ||Li all-solid-state cells exhibit a high initial discharge capacity of 151.1 mAh g −1 at 0.5C and retain 80.44% capacity after 200 cycles. This study elucidates a scalable and robust paradigm for designing high-safety, high-performance solid-state electrolytes for next-generation energy storage.