Nitrogen-doped nanoarray-modified 3D hierarchical graphene as a cofunction host for high-performance flexible Li-S battery

Lithium-sulfur (Li-S) batteries with high energy density are promising candidates for next-generation energy storage systems. Practical application of Li-S batteries is hindered by shuttle effect of polysulfides and Li dendrites growth. Herein, a self-supporting cofunction host is constructed with 3D hierarchical graphene modified by N-doped nanoarrays, for both Li anode and S cathode to improve their performances simultaneously. Attributed to high conductivity, strong affinity, and optimized Li-ion transport pathway of N-doped nanoarrays, cofunction host provide excellent Li and S load, which facilitates uniform Li deposition and enhanced S conversion. Particularly, an extra graphene barrier is specialized for S cathode to inhibit the shuttle effect. As a result, Li anode shows long cycle life with outstanding Li-plating behavior, and S cathode shows high capacity and ultrahigh capacity retention with good immobilization of polysulfides. More importantly, the integrated Li-S battery shows long cycle stability and good flexibility, which is important for future application.