Biomass-derived hard carbon microtubes with tunable apertures for high-performance sodium-ion batteries

• Published in: Nano research Vol. 16; no. 4; pp. 4874 - 4879
• Main Authors: Song, Pin, Wei, Shiqiang, Di, Jun, Du, Jun, Xu, Wenjie, Liu, Daobin, Wang, Changda, Qiao, Sicong, Cao, Yuyang, Cui, Qilong, Zhang, Pengjun, Ma, Liaobo, Cui, Jiewu, Wang, Yan, Xiong, Yujie
• Format: Journal Article
• Language: English
• Published: Beijing Tsinghua University Press 01-04-2023; Springer Nature B.V
• Subjects: Anodes; Apertures; Atomic/Molecular Structure and Spectra; Batteries; Biomedicine; Biotechnology; Carbon; Carbonization; Chemistry and Materials Science; Condensed Matter Physics; Diffusion barriers; Electrode materials; Energy storage; High temperature; Ion channels; Materials Science; Nanotechnology; Research Article; Sodium; Sodium-ion batteries; Wall thickness; sodium-ion batteries (SIBs); reversible capacity; long cycle life; hard carbon; kapok fibers
• ISSN: 1998-0124; 1998-0000
• DOI: 10.1007/s12274-022-5154-0

Sodium-ion batteries (SIBs) are considered the most up-and-coming complements for large-scale energy storage devices due to the abundance and cheap sodium. However, due to the bigger radius, it is still a great challenge to develop anode materials with suitable space for the intercalation of sodium ions. Herein, we present hard carbon microtubes (HCTs) with tunable apertures derived from low-cost natural kapok fibers via a carbonization process for SIBs. The resulted HCTs feature with smaller surface area and shorter Na
+
diffusion path benefitting from their unique micro-nano structure. Most importantly, the wall thickness of HCTs could be regulated and controlled by the carbonization temperature. At a high temperature of 1,600 °C, the carbonized HCTs possess the smallest wall thickness, which reduces the diffusion barrier of Na
+
and enhances the reversibility Na
+
storage. As a result, the 1600HCTs deliver a high initial Coulombic efficiency of 90%, good cycling stability (89.4% of capacity retention over 100 cycles at 100 mA·g
−1
), and excellent rate capacity. This work not only charts a new path for preparing hard carbon materials with adequate ion channels and novel tubular micro-nano structures but also unravels the mechanism of hard carbon materials for sodium storage.