Multi-heteroatom doped porous carbon derived from insect feces for capacitance-enhanced sodium-ion storage

The large-scale application of sodium ion batteries (SIBs) is limited by economic and environmental factors. Here, we prepare multi-heteroatom self-doped hierarchical porous carbon (HHPC) with a honeycomb-like structure by one-step carbonization method using high-yield and low-cost biomass silkworm excrement as a precursor. As an anode for SIB, HHPC-1100 exhibits a capacity of 331.7 mA h g⁻¹ at 20 mA g⁻¹, while it also reveals remarkable rate performance and stable long cycle capability due to its abundant pore structure and proper amount of hetero atom doping. Moreover, the synergistic effect of O, N, S, P co-doping in carbon materials on sodium ion adsorption is verified by the first-principles study, which provide a theoretical basis for the prominent electrochemical performance of the material.