Decomposition Pathway and Structural Transformation of Lithium Nickel Oxide Under a High-Delithiation State

Abstract

Two critical challenges for nickel-rich oxide cathode materials in Li-ion batteries are singlet oxygen evolution related to gassing/safety performance and irreversible phase transition associated with capacity fade, originating from the material’s decomposition at high states of charge. Therefore, it is significant to study the decomposition process and its structural transformation to inhibit the material’s multiple failures. Here, the first principle studied the decomposition process of lithium nickel oxide, which is similar to the decomposition behavior of nickel-rich oxide cathode materials. The calculation results show that the main resistance of the decomposition reaction of lithium nickel oxide under the high-delithiation state is the deoxygenation process, but the order of structural transformation and deoxygenation process of the cathode material is different.

Keywords: Lithium-ion batteries, Nickel-rich cathode material, Decomposition pathway, Lattice oxygen, Phase transition