Constructing advanced high-performance sodium-ion batteries anode materials via the morphology tuning strategy of lignin-derived carbon

Hard carbon as an ideal sodium-ion anode benefited from its superior performance and low cost. Generally, the lignin-derived hard carbons prepared by direct carbonization show poor performance. Regulating the morphology and microstructure is an effective strategy to enhance its performance. Herein, we designed three lignin-derived hard carbons to investigate the influence of the morphology of carbon materials on electrochemical performance. Specifically, we used self-assembly method, template method, and chemical activation to prepare the carbonaceous materials with different morphology. Electrochemical tests exhibited that self-assembled carbon nanospheres carbonized at 800 °C, solid carbon nanospheres, and carbon flakes are cycled for 100 cycles at a current density of 100 mA g−1, the reversible specific capacities of the above materials are 138.1 mAh g−1 and 83.1 mAh g−1, 130.9 mAh g−1, respectively. This study shows that both the microstructure and morphology play critical roles in sodium storage in carbon anode for SIBs.Graphic abstract