Rape seed shuck derived-lamellar hard carbon as anodes for sodium-ion batteries

Hard carbon with large interlayer spacing is suitable as the anode material for sodium-ion batteries. Rape seed shuck derived lamellar hard carbon is synthesized through hydrothermal and pyrolysis processes. As the anode, it exhibited good cycling stability, delivering a capacity of 143 mAh g−1 after 200 cycles at 100 mA g−1. The promising performances are attributed to the sheet structure with expanded interlayer distance (0.39 nm) and much void which can lower the sodium-ion insertion-extraction barrier and promote Na-ion diffusion and storage. The effect of pyrolysis temperature on the performance is also investigated.