Rapid Formation Strategy for Enhanced Electrochemical Performance of Hard Carbon Anodes in Sodium‐Ion Batteries

The conventional formation process of sodium‐ion batteries (SIBs), which relies on low‐current cycling, is one of the most energy‐intensive and time‐consuming steps in battery production, significantly contributing to overall manufacturing costs. This study systematically evaluates the formation of SIB pouch cells under different protocols and demonstrates that high‐rate formation can achieve superior electrochemical performance. Our optimized high‐rate formation process reduces formation time by 52.3% compared to the conventional method, presenting a cost‐effective and efficient approach to SIB production. Notably, the accelerated formation process promotes the development of a denser, more uniform, and highly stable solid‐electrolyte interphase (SEI) on the anode surface, enhancing initial Coulombic efficiency, capacity retention, and long‐term cycling stability. These findings provide a promising strategy for improving the scalability and economic viability of SIB technology.