The electrochemical properties of Co3O4 as a lithium-ion battery electrode: a first-principles study

Abstract

Extensive first principles calculations were performed to study the structural and electrochemical features of Co₃O₄ during its lithiation process as an anode material for lithium-ion batteries (LIBs). We found that with up to 8 mol Li in Co₃O₄, the formed Li_nCo₃O₄ structures are stable for low Li concentrations of n ≤ 1, but obvious structure distortions and volume expansions occur for Li_nCo₃O₄ with n > 1. This may be the reason why Co₃O₄ has a high Li capability but low cycling life as a LIB anode. The ab initio molecular dynamics simulations for Li_nCo₃O₄ (n = 2, 4, 8) further suggest a two-step electrochemistry process of Co₃O₄ → CoO → Co upon the lithiation process. We detected a distorted surface structure as Li atoms react with the Co₃O₄(110) surface, which also reduces the rate capability of the Co₃O₄ anode.