Metal Ion Catalysis within Hard Carbon Synthesis and Electrode Interface Engineering for Sodium-Ion Batteries

Metallic residues in biomass-derived hard carbons (HCs) are conventionally considered detrimental to Na⁺ ions storage, recent breakthroughs reveal that controlled metal-ion doping can substantially enhance electrochemical performance. Suitable metal doping is beneficial to enhance its overall performance. Consequently, manipulating the microstructure of HCs at the molecular level to achieve adaptive doping with metal ions, thereby fostering smoother diffusion environments and increasing storage sites for Na⁺ ions, is crucial for achieving exceptional sodium-ion batteries (SIBs) performance. This review delves into the commercialization potential of SIBs and provides a comprehensive summary of the development trajectory of metal ion-catalyzed hydrocarbons (MICHCs), which encompasses synthesis methodologies, the intricate relationship between metal doping position/content and performance, underlying reaction mechanisms. Regarding the catalytic mechanism of metal ions, this review outlines the interaction between metal ions and HCs, offering theoretical foundations and practical guidance for developing high-performance sodium storage materials. By regulating the content and type of metal ions, one can adjust the physicochemical properties of the local microstructure and improve the electrochemical properties of MICHCs. Research on MICHCs not only advances related disciplines but also fosters technological innovation and industrial upgrading. This review discusses the future developments and challenges facing key technologies in this burgeoning field.