Advancements in the Research of Biomass‐Based Hard Carbon Anode Materials for Sodium‐Ion Batteries

Sodium-ion batteries (SIBs) have shown great development potential in large-scale energy storage applications due to their advantages, such as abundant reserves,uniform distribution, low cost, and superior low-temperature performance. Of the various emerging carbon anode materials used in SIBs, biomass-based hard carbon (HC) is of particular interest due to its low cost, widespread availability, and excellent performance. However, there are problems with biomass-based HC materials, such as low initial Coulombic efficiency (ICE), low specific capacity, and poor rate performance. These issues make it difficult to meet current commercial demands. This article systematically reviews the structure and sodium storage mechanism of biomass-based HC materials, as well as the fine design of biomass-based HC anode materials, including structural engineering, interface engineering, and electrolyte engineering. It analyzes and summarizes the research progress on improving the ICE, specific capacity, and rate performance of biomass-based HC anode materials for SIBs. This review is expected to provide fundamental understanding and in-depth insights for the development of biomass-based HC anode materials for high-energy sodium storage.