A 3D metallic porous sulfurized carbon anode identified by global structure search for Na-ion batteries with fast diffusion kinetics

To overcome the main problems of low capacity and sluggish diffusion kinetics of carbon-based anodes for Naion batteries, we designed unique sulfurized carbon anode material (C8S) by using global structure search method combined with density functional theory, tight binding model, and deep-learning potential molecular dynamics. Different from the conventional semiconducting S-doped carbon, C8S is found to be metallic with high structural stability. Furthermore, it exhibits high reversible storage capacity of 465 mAh g-1, low diffusion barrier of 0.06 eV, and negligible volume change of 3.3 % in charging/discharging operation. In addition, the average open circuit voltage (0.64 V) ensures good safety during fast charging rates. These remarkable features make C8S a potential candidate anode for next-generation SIBs.