Theoretical studies of the solvent decomposition by lithium atoms in lithium-ion battery electrolyte

We have carried out density functional and ab initio calculations on the structure and stability of M-Li-n (n = 0, 1, and 2) complexes, where the M = ethylene carbonate (EC), propylene carbonate (PC), vinylene carbonate (VC), ethylene sulfite (ES), and glycol sulfate (GS). Although the molecules are geometrically similar, it is found that the reactions with lithium atoms may provide various reaction products depending upon the structures and stabilities. Reductive decomposition by lithium atoms appears to be in order of the most energetically favorable, ES similar to GS > EC similar to PC > VC, and GS > PC - EC similar to VC > ES for the first and second lithium atom addition reactions to the molecules, respectively. The transition states are also determined and discussed for EC, VC, and ES. (C) 2002 Elsevier Science B.V. All rights reserved.