Carbon material derived from biomass: a study of structural and electrochemical performances for dual-carbon sodium-ion batteries

Biomass is one of the attractive, renewable, widely available, and cost-effective precursors to obtain carbon. In this work, the carbon-based material derived from coconut shell was produced by carbonization method that is applicable for anode materials especially dual-carbon sodium-ion batteries. The as-synthesized coconut shell was burned to be a charcoal named as HC-A. The charcoal was further proceeded by heating using a furnace with the temperature of 1000 °C named as HC-B. Commercial hard carbon named as HC-C was also prepared to compare the quality of samples. The specific capacitance obtained from cyclic voltammetry test of sample HC-A, HC-B, and HC-C with a scan rate of 25 mV s⁻¹ are 6.73 × 10 − 3 F g⁻¹, 1.10 × 10 − 3 F g⁻¹ and 4.09 × 10 − 3 F g⁻¹, respectively. The Na⁺ ion diffusion coefficient of sample HC-A, HC-B and HC-C obtained from electrochemical impedance spectroscopy test are 5.75 × 10 − 15 cm 2 s − 1 , 2.85 × 10 − 15 cm 2 s − 1 , and 1.76 × 10 − 1 5 cm 2 s − 1 . The results display that carbon material from coconut shell and hard carbon commercial have comparable value indicating by the same order of electrochemical quantity. This comprehensive study provides a feasible method and opens new opportunities for biomass carbon, and extends the strategy to design the high-performance anode materials for batteries.