151. Hollow Si/SiOx nanosphere/nitrogen-doped carbon superstructure with a double shell and void for high-rate and long-life lithium-ion storage.
- Author
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Yang, Chao, Zhang, Yelong, Zhou, Jinhui, Lin, Chunfu, Lv, Fan, Wang, Kai, Feng, Jianrui, Xu, Zhikun, Li, Jianbao, and Guo, Shaojun
- Abstract
Silicon (Si) is a promising anode candidate for lithium-ion batteries (LIBs) owing to its unprecedented theoretical capacity of 4200 mA h g
−1 and earth-abundant supply (26.2 wt%). Nevertheless, the huge volume expansion and unstable solid-electrolyte interface (SEI) of Si in multiple cycles make it very hard to simultaneously achieve high-energy and long-term cycle life for applications in large-scale renewable energy storage. Herein, we demonstrate a new class of Si/SiOx @void@nitrogen-doped carbon double-shelled hollow superstructure (Si/SiOx -DSHS) electrodes that are capable of accommodating huge volume changes without pulverization during cycling. Benefiting from the unique double-shelled hollow superstructure, Si/SiOx -DSHSs can facilitate the formation of a highly stable SEI layer and provide superior kinetics toward Li+ -ion storage. The diffusion-controlled process and the capacitance-type reaction can work together to endow Si/SiOx -DSHSs with remarkable electrochemical characteristics, especially at high current density. These important characteristics make Si/SiOx -DSHSs deliver a large reversible capacity (1290 mA h g−1 at 0.1C), high first-cycle coulombic efficiency (71.7%), superior rate capability (360 mA h g−1 at 10C), and excellent cycling behavior up to 1000 cycles with a small capacity decay of 10.2%. The Si/SiOx -DSHSs are among the best Si-based anode materials for LIBs reported to date. [ABSTRACT FROM AUTHOR]- Published
- 2018
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