Enabling the ability of Li storage at high rate as anodes by utilizing natural rice husks-based hierarchically porous SiO2/N-doped carbon composites

Yi Feng, Li Liu, Xiaoyang Liu, Yifei Teng, Yixin Li, Yutong Guo, Yanchao Zhu, Xiaofeng Wang, Yimin Chao

Research output: Contribution to journalArticle

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Abstract

One of the greatest challenges in developing SiO 2/C composites as anode materials in lithium ion batteries (LIBs) is to improve the ability of Li storage at high rate over long-term cycles. Herein, biomass rice husks-based hierarchically porous SiO 2/N-doped carbon composites (BM-RH-SiO 2/NC) were prepared by ball mill and thermal treatment. BM-RH-SiO 2/NC can still retain a reversible capacity of 556 mAh g −1 over 1000 cycles at a high current of 1.0 A g −1. At 5.0 A g −1 the capacity is kept as high as 402 mAh g −1. This impressively long-term cyclic performance and high-rate capability of BM-RH-SiO 2/NC can be ascribed to the synergetic effect between the natural SiO 2 nanoparticles (< 50 nm) and the NC layer. The coating NC layer can not only effectively mitigate the volume strain during charge-discharge process to offer stably cyclic performance but also improve the electrical conductivity. Furthermore, the hierarchical porosity and better electrolyte wettability offer the rapid Li + diffusion and electron transfer, which enhance the pseudocapacitive behavior of whole electrode material and then guarantee fast electrochemical kinetics. Importantly, the unique Li-storage mechanism of active SiO 2 in BM-RH-SiO 2/NC composite was formed and found, which further validates the improved electrochemical capability.

Original languageEnglish
Article number136933
JournalElectrochimica Acta
Volume359
Early online date19 Aug 2020
DOIs
Publication statusPublished - 1 Nov 2020

Keywords

  • Electrochemical performance
  • Hierarchical porosity
  • Li-storage mechanism
  • Rice husks
  • SiO /N-doped carbon

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