Red phosphorus (P) is considered as an alternative anode material for high-energy-density lithium-ion batteries (LIBs) due to its high theoretical specific capacity and cost-effectiveness whereas practical application of phosphorus is severely hindered by the nature of low electrical conductivity and its huge volume change during the lithiation and delithiation process, leading to the failure of the electron conductive network and solid electrolyte interphase (SEI). Here, we reported a highly reversible P-based anode material for long-cycling and high-capacity LIBs. This hybrid anode (P-SP) is prepared with commercial red P and carbon black (Super-P) via ball-milling to obtain a nanoscale amorphous structure for excellent electron conductivity and minimized volume change. Furthermore, fluoroethylene carbonate (FEC) is introduced as an additive to form a LiF-rich SEI which enables stable cycling of a P-SP hybrid anode. As a result, the P-SP hybrid anode operating with the electrolyte of 10 vol % FEC exhibits a high capacity (2236.2 mAh g–1 at 0.3 C) and a stable cycling stability (86% retention of the second-cycle capacity after 300 cycles). With considerations of low-cost manufacture at a large scale and excellent electrochemical performances, our work may promote an effective strategy for practical application of P anode material in LIBs.

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The NASICON-type Li1.5Al0.5Ge1.5P3O12 (LAGP) ceramic electrolyte has the advantages of relatively high ionic conductivity, a wide electrochemical potential window, and air stability. However, side reactions and poor thermal stability between lithium metal and LAGP are enormous challenges. Here, we report a gel polymer electrolyte (GPE) interlayer composed of a solvate ionic liquid and a hyperbranched polyanionic copolymer to stabilize the Li|LAGP interface. The GPE with epoxy groups ensures excellent compatibility and protection between the LAGP and Li metal anode to suppress unfavorable reactions. Moreover, introducing a solvate ionic liquid with non-inflammability can effectively avoid the hidden danger of thermal runaway between lithium metal and LAGP at high temperatures (300 °C). The Li|GPE|LAGP|LiFePO4 full cell with the gel interface layer delivers a high reversible capacity of 139.5 mA h g–1 at 0.3 C and can stably cycle 300 times with a retention of 93.4%. This work provides an enlightening strategy for unstable electrolyte interfaces in promising, safe, and outstanding solid-state batteries.