Diatomite‐Derived Phosphorus‐Doped Carbon Electrodes Enhance the Energy Storage Performance of Sodium‐Ion Batteries

This paper introduces a self‐doped phosphorus (P)‐element hard carbon material synthesized from diatomite as a precursor through a high‐temperature carbonization process, along with a comprehensive evaluation of its electrochemical performance. The hard carbon material possesses a unique three‐dimensional porous structure enriched with P elements, which significantly enhances its electrochemical properties. This study systematically investigates the effects of different pyrolysis temperatures (700, 800, 900, and 1000 °C) on the microstructure and sodium‐ion storage performance of diatomite‐based hard carbon materials (DMs). Results indicate that the DM900 material, prepared at 900 °C, exhibits outstanding sodium‐ion storage performance, delivering high reversible specific capacities between 264.31 and 123.42 mAh g −1 at current densities between 0.02 and 2 A g −1 , respectively.