Multiferroic SmFeO3 reinforced polyvinylidene fluoride based solid-state electrolytes for lithium metal batteries

As the next-generation energy storage devices, solid-state lithium metal batteries have attracted much attention due to their excellent safety and high energy density. Polyvinylidene fluoride (PVDF) based polymer electrolytes offer several advantages, including high thermal stability, high electrochemical stability, and workability. The low ionic conductivity restricts their practical applications. In this work, composite solid-state electrolyte (CSE) membranes based on PVDF were prepared by incorporating multiferroic SmFeO 3 fillers. The SmFeO 3 fillers enhance lithium salt dissociation in CSEs, resulting in ionic conductivity as high as 1.50 × 10 −4  S cm −1 at 25 °C. Benefiting from the synergistic effect of the ferroelectric and ferromagnetic properties of the SmFeO 3 fillers, a robust and dense solid electrolyte interphase containing LiF is formed, Li-ions uniformly deposit on the surface of anode metallic lithium, thereby suppressing the formation and growth of lithium dendrites during the electrochemistry processes. The assembled Li|CSE|Li symmetric cells exhibit long-cycle performance (over 4800 h) under a current density of 0.1 mA h cm −2 at 25 °C. The Li|CSE|NCM811 batteries, assembled with LiNi 0.8 Co 0.1 Mn 0.1 O 2 (NCM811) as the cathode, exhibit good cycle stability with a capacity retention rate of 83% and an average coulombic efficiency of 99.3% after 200 cycles at a current density of 0.5C and 25 °C.