Nanjing Univ. (China). National Lab. of Solid State Microstructures, College of Engineering and Applied Sciences, Jiangsu Key Lab. of Artificial Functional Materials
SLAC National Accelerator Lab., Menlo Park, CA (United States); Stanford Univ., CA (United States)
Silicon demonstrates great potential as a next-generation lithium ion battery anode because of high capacity and elemental abundance. However, the issue of low initial Coulombic efficiency needs to be addressed to enable large-scale applications. There are mainly two mechanisms for this lithium loss in the first cycle: the formation of the solid electrolyte interphase and lithium trapping in the electrode. The former has been heavily investigated while the latter has been largely neglected. Here, through both theoretical calculation and experimental study, we demonstrate that by introducing Ge substitution in Si with fine compositional control, the energy barrier of lithium diffusion will be greatly reduced because of the lattice expansion. This effect of isovalent isomorphism significantly reduces the Li trapping by ~70% and improves the initial Coulombic efficiency to over 90%. We expect that various systems of battery materials can benefit from this mechanism for fine-tuning their electrochemical behaviors.
@article{osti_1597487,
author = {Zhu, Bin and Liu, Guoliang and Lv, Guangxin and Mu, Yu and Zhao, Yunlei and Wang, Yuxi and Li, Xiuqiang and Yao, Pengcheng and Deng, Yu and Cui, Yi and others},
title = {Minimized lithium trapping by isovalent isomorphism for high initial Coulombic efficiency of silicon anodes},
annote = {Silicon demonstrates great potential as a next-generation lithium ion battery anode because of high capacity and elemental abundance. However, the issue of low initial Coulombic efficiency needs to be addressed to enable large-scale applications. There are mainly two mechanisms for this lithium loss in the first cycle: the formation of the solid electrolyte interphase and lithium trapping in the electrode. The former has been heavily investigated while the latter has been largely neglected. Here, through both theoretical calculation and experimental study, we demonstrate that by introducing Ge substitution in Si with fine compositional control, the energy barrier of lithium diffusion will be greatly reduced because of the lattice expansion. This effect of isovalent isomorphism significantly reduces the Li trapping by ~70% and improves the initial Coulombic efficiency to over 90%. We expect that various systems of battery materials can benefit from this mechanism for fine-tuning their electrochemical behaviors.},
doi = {10.1126/sciadv.aax0651},
url = {https://www.osti.gov/biblio/1597487},
journal = {Science Advances},
issn = {ISSN 2375-2548},
number = {11},
volume = {5},
place = {United States},
publisher = {AAAS},
year = {2019},
month = {11}}
Materials for Sustainable Energy: A Collection of Peer-Reviewed Research and Review Articles from Nature Publishing Group, p. 187-191https://doi.org/10.1142/9789814317665_0026