Abstract
Group IVA elements (Si, Ge and Sn) are promising candidates for the anode materials of lithium ion batteries (LIBs) due to their large theoretical specific capacities. However, serious problems of pulverization and capacity degradation resulted from the huge volume changes during charge/discharge operations hindered their successful applications as the anode materials in the LIBs. In this work, diffusion behaviors of Li ions in Si(100) and Si(111) slabs with a piezoelectric field applied perpendicularly to the surfaces were investigated using density functional theory. Results showed that the diffusivity of the Li in Si can be significantly enhanced by applying the electric field generated from the piezoelectric material. This finding can explain well the recent experimental observations in which improved electrochemical performance was obtained using Si/carbon nanotube/BaTiO3 as the anode for the LIBs. New generation of anode composite materials can be designed based on this idea and the piezoelectric material is used not only to accommodate the volume variation of active materials of Si, but also to enhance the charging rate of the LIBs.
Original language | English |
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Journal | ChemElectroChem |
DOIs | |
Publication status | Published - 7 Apr 2017 |
Keywords
- Piezoelectric material
- Si anode
- Lithium ion batteries
- Density functional theory