Ab Initio Calculations of Thermal Decomposition Mechanism of LiPF6-Based Electrolytes for Lithium-Ion Batteries

Author:
  • YOYasuharu Okamoto
    Yasuharu Okamoto
Publisher website
Google Scholar
Abstract
Ab initio molecular orbital calculations were done to examine the thermal decomposition mechanism of LiPF6-based electrolyte such as LiPF6 dissolved into carbonate ester. We focused our study on LiPF6 decomposition (LiPF6 + H2O → LiF + POF3 + 2HF) and ethylene carbonate decomposition (EC + POF3 → CO2 + CH2FCH2OPF2O). Intrinsic reaction coordinate calculations showed that the latter reaction has a significantly high reaction barrier more than 3 eV. However, we found that it may be reduced by 0.97 eV by considering PF6 − ion which acts as a kind of catalyst in the reaction. Although POF3 triggers EC ring opening reaction unless both Li+ and PF6 − ions are considered in the model, it remains a spectator in the C-O bond breaking reaction of diethyl carbonate (DEC) by PF6−. © 2013 The Electrochemical Society. [DOI: 10.1149/2.020303jes] All rights reserved. Manuscript submitted October 4, 2012; revised manuscript received December 12, 2012. Published January 2, 2013. Enabling the long-term operation of lithium-ion batteries (LIBs) is necessary for expanding its application to new fields such as electric vehicles or stationary batteries because their product lifetime is much longer than the mobile devices that are the major market for the current LIBs. In addition to the higher reliability, the improvement of cycle and calendar life is a primary target for the development o

This publication has 19 references indexed in Scilit: