Invited Talks: Transition Metal Oxides - University Blog Service - The ...

The John B. Goodenough Symposium in Materials Science & Engineering –
In Honor of His 90 th Birthday
The University of Texas at Austin, Austin, Texas
October 26-27, 2012
First-Principles Study of Li Defect in Solid Electrolyte (γ-Li 3 PO 4 ) and in
Electrode/Electrolyte (Li/γ-Li 3 PO 4 ) interface
Santosh KC 1 , Ka Xiong 1 , Roberto C. Longo 1 , and Kyeongjae Cho 1, 3 *
1 Department of Materials Science and Engineering, University of Texas at Dallas, Richardson, TX 75080, USA
3 Department of Physics, University of Texas at Dallas, Richardson, TX, 75080, USA
*Email: kjcho@utdallas.edu
Abstract:
In this work, we present our results of first-principles calculations of defects in solid electrolyte γ-Li 3 PO 4
and in negative electrode/electrolyte interface (Li/γ-Li 3 PO 4 ). Our results show that Li interstitial defect
dominates over the vacancy defect. The Li vacancy-interstitial pair defect formation energy of the
interface model is comparable to the sum of Li vacancy defect at the electrode and Li ion (Li + ) interstitial
defect in the electrolyte. Our study shows that the high Li + defect formation energy is the determining
factor for low ionic conductivity of this Li metal/electrolyte interface. Thus, the study of the Li
metal/electrolyte interface provides information on Li defect formation and migration, which will help us
to improve the ionic conductivity in future Li-ion battery.