Hierarchical Pore Engineering of Slope‐Type Hard Carbon for Enhanced Sodium‐Ion Storage

Designing hierarchical porous structures is widely recognized as an effective strategy to improve ion transport and create active sites for disordered carbon anodes of sodium‐ion batteries (SIBs). Herein, hierarchical porous hard carbon (hp‐HC) is synthesized using zinc acetate as a templating agent. The hierarchical porous structure facilitates effective Na+ ion storage with a high reversible capacity of 327 mA h g−1 at a current density of 0.1 A g−1. Notably, the sodium storage behavior is capacitance‐dominated, with the capacity primarily characterized by slope capacity. Additionally, the hp‐HC retains 94.5% of its capacity after 6000 cycles at 1.0 A g−1. This work provides a convenient route for manipulating pore types, which is of great significance for developing high‐capacity hard carbon electrodes for enhanced sodium‐ion storage.