ZnO dual-functional template-assisted construction of hierarchical porous hard carbon anode for high-rate sodium storage

Hard carbon has emerged as the most widely studied and commercialized anode material for sodium-ion batteries (SIBs). However, improving the charge transfer kinetics within the plateau potential range of the hard carbon anode is crucial for the development of fast-charging SIBs. In this study, we prepared a novel composite material, ZAPA-1300, by uniformly mixing starch, asphalt, and zinc oxide (ZnO), followed by a two-step treatment process. ZnO functions as a dual function as both a defoaming agent and a crosslinking agent, facilitating the uniform coating of starch particles with asphalt and promoting the formation of a mesoporous structure. The ZAPA-1300 achieves an initial Coulombic efficiency (ICE) of 77.92 % at 0.1C (1C = 300 mA g^-1) and exhibits a remarkable high-rate capability, delivering a discharge capacity of 168.3 mAh g^-1 at 20C. Kinetic analysis indicates that the abundant open-pore structure promotes charge transfer and ion diffusion. Our study highlights the potential of ZnO as a dual-functional agent for the development of high-performance anodes for SIBs and provides valuable guidance for the synthesis of high-rate hard carbon materials.