Reconfiguring Terminal Species of Bituminous Coal to Steer Hard Carbon toward High‐Capacity and Fast Sodium Storage

Hard carbons derived from coal precursors have shown bright industrial prospect as the low cost anode materials of sodium‐ion batteries. However, it is of extreme necessity yet challenge to regulate carbon microstructure toward superior sodium energy storage. In this study, we propose a powerful chemical reconfiguration tactic to steer hard carbons toward high‐capacity and fast sodium storage. The functional species on the edge/plane terminals of bituminous coal are finely reconfigured by nitri‐oxidation treatment for effectively inhibiting the reordering of carbon layers under high temperature, thereby creating rich ultramicropores/closed pores and expanded interlayer spacing. These structural merits enable the hard carbon to garner an enhanced capacity of 356 mAh g−1 along with a high initial Coulombic efficiency of 88.1% and long lifespan. More impressively, the sodium storage kinetics is substantially sped up with a large capacity of 215 mAh g−1 retained at a high‐rate of 2 A g−1. This work will afford a fresh methodology for precursor modulation to accelerate the real‐world practice of hard carbons toward advanced sodium‐ion batteries.