Zhenyuan Xie, Qingsang He, Yongling Men, Ziyi Zhu, Zhang Ye, X. F. Li, Zhang Ye
The intensive synergy between mineral resource utilization and energy storage battery technology is emerging as a core driver of the energy transition. Among alternatives, sodium-ion batteries have garnered significant interest due to the natural abundance and cost advantages. Hard carbon stands as the only commercially implemented anode material, with its performance being pivotal to the overall cell performance. This review focuses on key challenges facing hard carbon, including the capacity threshold constraint, kinetic limitations, and unclear sodium storage mechanisms. It critically evaluates recent advances in mechanism elucidation, microstructure modulation, and doping modification, and provides perspectives on future research directions.