Construction of hollow core–shell Sb2S3/S@S-doped C composite based on complexation reaction for high performance anode of sodium-ion batteries

Abstract

Although the high-capacity Sb2S3-based anode materials for sodium-ion batteries can combine the advantages of multi-step conversion of Sb2S3 to Sb and alloying reaction between Sb and Na for improving the performance, the slow reaction kinetics, low electronic conductivity, and poor reversibility of the sodium storage process have limited their practical application. To effectively improve the electrochemical performance, a three-dimensional Sb2S3/S@S-doped carbon composite with a hollow core–shell structure based on the combination of template method and coupling reaction is successfully synthesized. By combining the finite element simulation, dynamic analysis, and density functional theory calculation, the respective roles of S-composite and hollow core–shell structure in boosting performance are revealed. The internal S and external S-doped carbon can interact with Sb2S3 to improve its reactivity with Na+, and effectively release the stress of Sb2S3 in the sodiation process. The S-doped carbon can accelerate Na+ diffusion and further stabilize the structure of Sb2S3. Benefited from the special structure, the as-prepared anode displays high reversible capacity, superior cycle performance and high rate capability. The assembled full battery also exhibits an excellent energy density under high power, and can still maintain a high reversible capacity of 310 mAh/g at 1 A/g over 500 cycles.