1. In Situ TEM of Phosphorus-Dopant-Induced Nanopore Formation in Delithiated Silicon Nanowires
- Author
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Xiaobo Shi, Jiakun Zhu, Hui Yang, Yuemei Liu, Meng Gu, Feifei Fan, and Mohan Guo
- Subjects
In situ ,Materials science ,Dopant ,Nanoporous ,chemistry.chemical_element ,02 engineering and technology ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Electrochemistry ,01 natural sciences ,0104 chemical sciences ,Anode ,Nanopore ,chemistry ,Chemical engineering ,Phase (matter) ,General Materials Science ,Lithium ,0210 nano-technology - Abstract
Through in situ transmission electron microscopy (TEM) observation, we report the behaviors of phosphorus (P)-doped silicon nanowires (SiNWs) during electrochemical lithiation/delithiation cycling. Upon lithiation, lithium (Li) insertion causes volume expansion and formation of the crystalline Li15Si4 phase in the P-doped SiNWs. During delithiation, vacancies induced by Li extraction aggregate gradually, leading to the generation of nanopores. The as-formed nanopores can get annihilated with Li reinsertion during the following electrochemical cycle. As demonstrated by our phase-field simulations, such first-time-observed reversible nanopore formation can be attributed to the promoted lithiation/delithiation rate by the P dopant in the SiNWs. Our phase-field simulations further reveal that the delithiation-induced nanoporous structures can be controlled by tuning the electrochemical reaction rate in the SiNWs. The findings of this study shed light on the rational design of high-power performance Si-based anodes.
- Published
- 2019