N,S‐Doped Porous Carbon Nanobelts Embedded with MoS2 Nanosheets as a Self‐Standing Host for Dendrite‐Free Li Metal Anodes

Metallic Li is one of the most promising anodes for high-energy secondary batteries. However, the enormous volume changes and severe dendrite formation during the Li plating/stripping process hinder the practical application of Li metal anodes (LMAs). We have developed a sulfate-assisted strategy to synthesize a self-standing host composed of N,S-doped porous carbon nanobelts embedded with MoS2 nanosheets (MoS2 @NSPCB) for use in LMAs. In situ measurements and theoretical calculations reveal that the uniformly distributed MoS2 derivatives within the carbon nanobelts serve as stable lithiophilic sites which effectively homogenize Li nucleation and suppress dendrite formation. In addition, the hierarchical porosity and 3D nanobelt networks ensure fast Li-ion diffusion and accommodate the volume change of Li deposits during the plating/stripping process. As a result, a Li-Li symmetric cell using the MoS2 @NSPCB host operates steadily over 1500 h with an ultralow voltage hysteresis (≈24.2 mV) at 3 mA cm-2 /3 mAh cm-2 . When paired with a LiFePO4 cathode, the current collector-free LMA endows the full cell with a high energy density of 460 Wh kg-1 and good cycling performance (with a capacity retention of ≈70% even after 1600 cycles at 10 C).