Construction of 3D hierarchical honeycomb macro/meso/micro-porous carbon with soft and hard templates for high-performance sodium-ion batteries

3D hierarchical honeycomb carbon with plentiful macropores, mesopores, micropores is constructed with SiO2 nanospheres and microspheres as hard template, diverse boiling bubbles as soft template, and polyvinyl pyrrolidone as the assembling agent and carbon source. Hierarchical honeycomb carbon calcined at 1000 ℃ delivers discharge capacity of 146 mAh/g at 1 A/g after 3000 cycles, average discharge capacity of 206 mAh/g at 0.5 A/g and 98 mAh/g at 5 A/g. High reversible capacity, stable cycling performance and good rate capability mainly benefit from the hierarchical honeycomb porous structure with high defects, high porosity and large surface area, demonstrating that it is an outstanding anode material for sodium-ion batteries.