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. A novel hierarchical cofunction host with N‐doped nanoarray‐modified graphene is fabricated for Li anode and S cathode simultaneously. Combining the advantages of structure design and morphology optimization with chemical interactions and physical confinements, flexible and high‐performance lithium‐sulfur batteries are achieved with excellent capacity retention and long cycle life.