Intrinsic mechanisms for structural coherency and electrochemical excellence in layered-spinel Li–Mn–O cathodes

Abstract

As the demand for lithium-ion batteries rises in consumer electronics, electric vehicles and stationary energy storage industries, there is both an opportunity and a need to innovate the cathode materials. Manganese-rich metal oxide cathodes have the potential to replace state-of-the-art cobalt- and nickel-rich layered electrode systems, which rely on metals that are scarce, high-cost, toxic, and unsafe. One approach is to use structurally compatible, manganese-based components such as layered Li₂MnO₃ and spinel Li_1+yMn_2−yO₄ to reduce the Co and Ni content, thereby stabilizing lithium- and manganese-rich with nickel–manganese–cobalt (LMR-NMC) electrodes. A current study reports a detailed structural investigation of the baseline “layered-spinel” system xLi₂MnO₃·(1 − x)Li_1+yMn_2−yO₄ (0 ≤ y ≤ 0.33) using synchrotron X-ray diffraction, high-resolution transmission electron microscopy, and high-resolution Raman spectroscopy. This provides insights into the complexity of this system and reveals clues that may assist in improving the electrochemical properties and stability of structurally integrated “layered-layered-spinel” LMR-NMC electrodes for high-energy lithium-ion battery systems.