Recent Advances, Key Strategies, and Challenges in Fast‐Charging Hard Carbon Anodes for Sodium‐Ion Batteries

Abstract Sodium‐ion batteries (SIBs) have gradually entered the application market after years of development. To enhance user experience and reduce waiting time, the development of fast‐charging SIBs has become an inevitable trend. However, hard carbon (HC) anode materials currently in use face significant challenges, such as capacity degradation and sodium metal plating during fast‐charging. This paper explores the entire process of Na + migration from the electrolyte to the bulk phase of the HC and examines the factors influencing Na + migration at each stage. It then summarizes key strategies for achieving fast‐charging HC for SIBs, with a focus on electrolyte optimization, surface coating, and bulk structural optimization. Finally, the paper highlights the main challenges and future prospects for developing fast‐charging HC anodes, offering valuable insights for advancing fast‐charging SIBs technologies.