The study investigates the stability limits of layered transition metal oxides (LiMO2) with higher nickel content as cathode active materials (CAMs). The improved performance is attributed to the lower potential of nickel-rich CAMs, which prevents detrimental electrolyte oxidation. The research finds that the stability of CAMs is determined by their composition and structural stability during delithiation, with lattice oxygen release being the primary cause of CAM degradation, as revealed by on-line electrochemical mass spectrometry (OEMS) during short-term and extended cycling experiments.

The Structural Stability Limit of Layered Lithium Transition Metal Oxides Due to Oxygen Release at High State of Charge and Its Dependence on the Nickel Content / Oswald, S. and Gasteiger, H. A. / J. Electrochem. Soc. 2023, 170 030506 (Open Access)  - DOI