Sucrose-anthracite composite supplemented by KOH&HCl washing strategy for high-performance carbon anode material of sodium-ion batteries

Sodium-ion batteries represent a promising alternative to lithium-ion batteries, necessitating research into cost-effective synthesis of high-performance anode materials. Herein, this work proposes a facile method combining sucrose-anthracite composites with KOH&HCl decontamination to produce soft/hard carbon hybrids. This approach enhances the structural stability of the material to optimize the carbon yield and increases the interlayer spacing and microcrystalline disorder. The presence of numerous defect sites and C=O active double bonds within the structure, coupled with the flaky morphology, results in an outstanding carbon anode material, exhibiting a high specific capacity of 272 mAh g⁻¹ with excellent rate performance (229 mAh g⁻¹ at 10 C). Furthermore, the material maintains 80 % capacity over 1300 cycles at a high current density of 10 C. The optimization in structure and morphology, along with enhanced electronic conductivity and ionic diffusion kinetics, also ensures that the capacity of the material is dominated by plateau capacity at any current density, which is beneficial for increasing the energy density of full battery configurations and holds promise for high-performance sodium-ion battery anode materials.