| AVS 60th International Symposium and Exhibition | |
| Energy Frontiers Focus Topic | Wednesday Sessions |
| Session EN+SE+SS+TF-WeM |
| Session: | Thin Films for Energy |
| Presenter: | B.B. Kappes, Colorado School of Mines |
| Authors: | C. Ban, National Renewable Energy Laboratory B.B. Kappes, Colorado School of Mines Q. Xu, National Renewable Energy Laboratory C. Engtrakul, National Renewable Energy Laboratory C.V. Ciobanu, Colorado School of Mines A.C. Dillon, National Renewable Energy Laboratory Y. Zhao, National Renewable Energy Laboratory |
| Correspondent: | Click to Email |
We demonstrate the reversible lithiation of SiO2 up to 2/3 Li per Si, and propose a mechanism for it based on molecular dynamics and density functional theory simulations. Our calculations show that neither interstitial Li (no reduction), nor the formation of Li2O clusters and Si–Si bonds (full reduction) are energetically favorable. Rather, two Li effectively break a Si–O bond and become stabilized by oxygen, thus partially reducing the SiO2 anode: this leads to increased anode capacity when the reduction occurs at the Si/SiO2 interface. The resulting LixSiO2 (x < 2/3) compounds have electronic band gaps in the range of 2.0–3.4 eV. (Published in Applied Physics Letters 100 (2012) 243905.)