Experimental design and theoretical calculation for sulfur-doped carbon nanofibers as a high performance sodium-ion battery anode

• Published in: Journal of materials chemistry. A, Materials for energy and sustainability Materials for energy and sustainability, 2019, Vol.7 (17), p.1239-1245
• Main Authors: Jin, Qianzheng, Li, Wei, Wang, Kangli, Feng, Pingyuan, Li, Haomiao, Gu, Tiantian, Zhou, Min, Wang, Wei, Cheng, Shijie, Jiang, Kai
• Format: Article
• Language: English
• Subjects: Anodes; Batteries; Carbon; Carbon fibers; Cellulose; Covalent bonds; Crosslinking; Design of experiments; Electrochemistry; Electrode materials; Electronegativity; Experimental design; First principles; Industrial wastes; Interlayers; Nanofibers; Rechargeable batteries; Sodium; Sodium-ion batteries; Sulfur; Sustainable development
• ISSN: 2050-7488; 2050-7496
• DOI: 10.1039/c9ta02107h

Hard carbon is one of the most promising anode materials for sodium ion batteries (SIBs) due to its low cost, high conductivity and suitable potential; however, its application is hindered by its relatively low capacity, and unsatisfactory rate capability and cyclability. Herein, we have reported a high performance SIB anode of S-doped interconnected carbon nanofibers (denoted as S-CNFs) that was directly derived from the industrial waste product bacterial cellulose, demonstrating great potential for practical application and sustainable development. The S-CNFs present high reversible capacities of 460 mA h g −1 at 0.05 A g −1 and 255 mA h g −1 at 10 A g −1 , and preserved a capacity of 310 mA h g −1 at 1 A g −1 after 1100 cycles. Structural and electrochemical analyses revealed that multiple factors including the expanded (002) interlayer spacing, the electrochemically active -C-S-C- covalent bonds, the capacitive process induced by a large surface area and considerable defects as well as the stable structure associated with the cross-linked network contributed to their excellent performance. Furthermore, the first principles evaluations confirmed the sodium-storage mechanism of sulfur doping, which not only improved the interlayer distance for the mobility of Na + but also promoted the electronegativity as well as the electrochemical activity and increased the adsorption of Na + . S-doped carbon nanofibers derived from bacterial cellulose with interlinked networks and pores were facilely prepared in a sustainable approach. This product presents a high Na-ion storage capacity and excellent rate performances.