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Thermal pyrolysis of Si@ZIF-67 into Si@N-doped CNTs towards highly stable lithium storage.
- Source :
-
Science Bulletin . Mar2020, Vol. 65 Issue 6, p452-459. 8p. - Publication Year :
- 2020
-
Abstract
- Thermal pyrolysis of Si@ZIF-67 yields Si@N-doped CNTs in situ, exhibiting a highly reversible electrochemical lithium storage capacity. Silicon is attracting considerable attention as an active anode material for advanced lithium-ion batteries due to its ultrahigh theoretical capacity. However, the reversible utilization of silicon-based anode materials is still hindered by the rapid capacity decay, as a consequence of the huge volume change of silicon during cycling. Herein, we use a Co-zeolitic imidazole framework (ZIF-67) to prepare silicon-wrapped nitrogen-doped carbon nanotubes (Si@N-doped CNTs) by controllable thermal pyrolysis. The as-prepared nanocomposites can effectively prevent pulverization and accommodate volume fluctuations of silicon during cycling. It can deliver a highly reversible capacity of 1100 mAh g−1 even after 750 cycles at a current density of 1000 mA g−1. As confirmed by an in situ transmission electron microscopy experiment, the remarkable electrochemical performance of Si@N-doped CNTs is attributed to the high electronic conductivity and flexibility of cross-linked N-doped CNTs network as a cushion to mitigate the mechanical stress and volume expansion. Furthermore, a full cell consisting of Si@N-doped CNTs anode and LiFePO 4 cathode delivers a high reversible capacity of 1264 mAh g−1 and exhibits good cycling stability (>85% capacity retention) over 140 cycles at 1/4 C (1 C = 4000 mA g−1) rate. [ABSTRACT FROM AUTHOR]
Details
- Language :
- English
- ISSN :
- 20959273
- Volume :
- 65
- Issue :
- 6
- Database :
- Academic Search Index
- Journal :
- Science Bulletin
- Publication Type :
- Academic Journal
- Accession number :
- 142207066
- Full Text :
- https://doi.org/10.1016/j.scib.2019.12.005