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

作者：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^*

来源：Nano Research, 2023, 16(4): 4874-4879.

DOI：10.1007/s12274-022-5154-0

• hard carbon
• kapok fibers
• sodium-ion batteries (SIBs)
• reversible capacity
• long cycle life

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 degrees 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.

• 单位
  南京理工大学; 南开大学; 中国科学院