Constructing Durable High-Voltage PVDF-Based Solid-State Lithium Metal Batteries via an All-in-One Design

Poly(vinylidene fluoride) (PVDF)-based solid electrolytes represent a compelling frontier for solid-state lithium metal batteries. Unfortunately, their practical implementation is severely impeded by high Li⁺ migration energy barrier and pronounced interfacial instabilities, arising from α-phase-rich conformations and undesired Li⁺-solvation environments. In this study, an 'all-in-one' regulation strategy enabled by N-methylimidazolium bis((trifluoromethyl)sulfonyl)imide (MimTFSI) is proposed, which synergistically engineers a β-phase polymer matrix for shortened pathways and constructs an anion-rich solvation sheath for lowered energy barriers, ultimately unlocking fast and stable Li⁺ transport coupled with exceptional interfacial compatibility. Consequently, this integrated solid-state electrolyte demonstrates a high ionic conductivity of 0.84 mS cm^{- 1}, supports stable cycling of Li symmetric cells for over 4000 h at 0.1 mA cm^{- 2}, and delivers outstanding cycling performance in Li/LiNi_0.8Co_0.1Mn_0.1O₂ full cells, retaining 93.8% of its initial capacity after 930 cycles at 0.5 C and 95% over 500 cycles at 1 C. Even under expanded voltage windows, it retains 80% after 580 cycles at 4.4 V and 84% after 160 cycles at 4.5 V. Furthermore, the pouch cell is capable of delivering a discharge capacity of 3.26 mAh cm^-2, demonstrating the strong applicability for next-generation solid-state lithium metal batteries.