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 0.8 Co 0.1 Mn 0.1 O 2 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.