Pre-crosslinking enables a promising cyclodextrin-derived carbon anode with large plateau capacity for sodium ion batteries

• Published in: New journal of chemistry 2024-01, Vol.48 (3), p.1182-1191
• Main Authors: Ding, Haifeng, Yue, Liang, Liu, Yonghang, Zhang, Yi, Zhao, Qing, Zhi, Peipei, Qi, Yuruo, Xu, Maowen
• Format: Article
• Language: English
• Subjects: Batteries; Binding sites; Carbon; Carbonyl groups; Carbonyls; Crosslinking; Cyclodextrins; Sodium-ion batteries
• ISSN: 1144-0546; 1369-9261
• DOI: 10.1039/d3nj04843h

Cyclodextrin, which has the advantages of being resource-rich, low cost, eco-friendly, high purity and good stability, is a potential precursor to prepare hard carbons for sodium ion batteries (SIBs), but is rarely explored so far. In this work, a simple and commercializable pre-crosslinking strategy was developed to modulate the local structure of cyclodextrin-derived carbons, because the direct carbonization of cyclodextrin leads to a limited capacity of 154.7 mA h g −1 . The original cyclic monomer structure of cyclodextrin is transformed into a three-dimensional cross-linked structure via carbonyl groups as binding sites. The cross-linking reaction tends to produce more sp 3 -hybrid carbon, which finally results in more curved and shorter carbon layers as well as much more closed pores. Thus, the best sample obtained with a thirty-minute pre-crosslinking treatment delivers an improved reversible specific capacity of 332.5 mA h g −1 at a current density of 30 mA g −1 with an initial Coulombic efficiency of 83.4%, where the low-voltage plateau region (230.1 mA h g −1 ) contributes up to 70% of the total capacity. To the best of our knowledge, this work offers a tentative exploration of cyclodextrin-derived carbons for the first time, which possibly opens up the investigation of this new kind of carbon anode. The cross-linking reaction tends to produce more sp 3 -hybrid carbon, which finally results in more curved and shorter carbon layers as well as much more closed pores. Therefore, we can regulate the closed pores and platform capacity.