Lithophilic SnO2-reinforced carbon fiber-based composite anode for high-performance lithium metal batteries

Abstract

Lithium metal batteries are among the most promising energy storage systems due to the high energy density. However, its practical application is hindered by growing lithium dendrite and unstable solid electrolyte interphase. Three-dimensional conductive collectors have been widely proposed to solve the above problems, while their lithophobic behavior has no favorable effect on lithium plating/stripping. Composite anode (CF@SnO₂-1.0@Li) with homogeneous SnO₂ lithophilic sites are prepared, the lithium nucleation barrier is lowered through SnO₂, and homogeneous deposition of lithium ions is induced, and consequently the growth of lithium dendrites and the formation of “dead Li” are suppressed. The CF@SnO₂-1.0@Li symmetrical cells can stable cycle for more than 2200 h at 1 mA cm⁻² and 1 mAh cm⁻². The assembled LiFePO₄ full cell exhibits a high initial discharge capacity of 145.1 mAh g⁻¹ and a high capacity retention rate of 94.3% after 300 cycles at 1 C. Similarly, the assembled LiCoO₂ full cell shows outstanding rate performance and cycling stability. This study provides a new strategy for the development of ultrastable lithium metal batteries.