Tailored Work Function by N, Si Co‐Doping Enables High‐Performance Hard Carbon Anode for Lithium‐Ion Batteries

Abstract Developing high‐rate and high‐capacity hard carbon anode is crucial for improving the power and energy density of lithium‐ion batteries. Herein, a nitrogen–silicon co‐doped hard carbon anode (N─Si─HC) is proposed derived from biomass macadamia nut shell. Theoretical calculations confirm that nitrogen–silicon co‐doping can effectively reduce the surface work function and facilitate lithium ions adsorption and migration. Moreover, the N─Si─HC anode demonstrates significantly alleviated electrochemical concentration polarization and stress accumulation. As a consequence, the N─Si─HC anode with optimized sintering temperature reveals superior electrochemical performance. Specifically, a high reversible capacity of 158 mAh g −1 is reached at 10 C, and the capacity retention rate is 84.2% after 2000 cycles, and an ultra‐long cycle stability of 10 000 cycles is achieved. In addition, the N─Si─HC anode with mechanically stable solid electrolyte interphase (SEI) exhibits a reduced desolvation barrier and enhanced pseudocapacitive lithium storage capacity. More importantly, this study provides a practical guidance for designing high‐performance hard carbon anodes.