PVDF-HFP layer with high porosity and polarity for high-performance lithium metal anodes in both ether and carbonate electrolytes

Abstract

Lithium metal batteries hold great promise for high-energy-density rechargeable battery systems. However, Li metal anode suffer from poor stability and safety hazards in liquid electrolytes due to uncontrollable Li dendrites growth and unstable solid-electrolyte interphase (SEI). Herein, this work constructs a porous PVDF-HFP layer (PPHL) with high polarity as interfacial layer for dendrite-free and stable Li metal anodes in both ether and carbonate electrolytes. PPHL can not only physically suppress the Li dendrites owing to high mechanical strength, but also regulate the even Li-ion flux due to porous and highly polar β phase structure. “LiF-rich” SEI induced by PPHL is found responsible to enhance the stability of SEI and improve Li-ion diffusion for stable Li plating/stripping behaviors. Therefore, Li metal with PPHL shows uniform and dense Li deposition without Li dendrites. Li/Li symmetric cells exhibit high stability and reversibility in ether electrolyte for 1400 h and carbonate electrolyte for 600 h with high Li-ion transference number. Li//LFP full battery shows excellent cyclic stability and rate performance with high capacity retention in commercial carbonate electrolyte.