Understanding the regulation of sulfur on surface-dominated hard carbon anode for sodium ion batteries

• Published in: Journal of power sources 2025-01, Vol.625, p.235685, Article 235685
• Main Authors: Li, Mingyang, Li, Zijian, Song, Hongze, Harudin, Nurhidayu, Kufian, Mohd Zieauddin, Woo, Haw Jiunn, Osman, Zurina
• Format: Article
• Language: English
• Subjects: Excellent cycle properties; S-doped porous carbon; Sodium-ion batteries; Surface-dominated capacity
• ISSN: 0378-7753
• DOI: 10.1016/j.jpowsour.2024.235685

To tune electronic conductivity and improve capacity and stability of hard carbon anodes in sodium-ion batteries (SIBs), sulfur (S) atom doping is considered an effective approach. However, the relationship between S-regulation and the surface capacitive behavior is still unclear. This work obtains in-situ S-doped porous carbon materials (SPCs) with S-containing species varying with calcination temperature. This work discovers that S-regulation has a modulating effect on all sodium storage stages: “adsorption-intercalation-pore filling”. In surface-dominated process, C-S, chain sulfur bonds, and C-SO2 bonds with effective negative potentials are considered have higher adsorb capability, providing additional adsorption sites for SPCs. During intercalation stage, the balance between the interlayer spacing and the graphitization degree of SPCs, can promote satisfactory intercalation capacity. Additionally, the S-containing inorganic templates provides sufficient mesopores for SPCs, enabling efficient sodium storage during the pore-filling stage. The SPC carbonized at 600 °C with regulated S-doping provides 260.5 mAh g−1 and 721.4 mAh g−1 at 50 mA g−1 in SIBs and lithium-ion batteries (LIBs), and shows a high retention of 92.9 % and 95.4 % after 50th in SIBs and LIBs full-cells. This work provides guidance for understanding the contribution of S-regulation to surface-domainted capacitive behavior and designing tailor-made S-regulated carbon anodes. [Display omitted] •Comprehensive explore the S regulation among entire sodium storage stages.•Revealing S-containing functional groups promote surface-dominated capacity.•Achieving long-cycle stability in SIBs/LIBs basing on S regulation.