Enhancing the stability of Li-Rich Mn-based oxide cathodes through surface high-entropy strategy

Li-rich Mn-based layered oxides (LMR) hold promise as cathode materials for lithium-ion batteries (LIBs) due to their high reversible capacity. However, issues such as oxygen release and structural degradation associated with oxygen redox cause voltage decay and capacity decline during cycling. In this study, a monodisperse Li1.2Ni0.13Co0.13Mn0.54O2 cathode material with surface high-entropy architecture (MZCN-LMR) was synthesized to enhance the overlap between the non-bonding orbitals of oxygen (|O2p) and the (TM-O)* occupied band. This enhancement enables regulation of the depth of oxygen oxidation, improving reversible oxygen redox and creating highly flexible structures, with mitigated anisotropic modulus and lattice strain evolution during (de) intercalation. Consequently, the developed MZCN-LMR cathode exhibits impressive capacity retention of 80.5 % after 400 cycles and minimal voltage decay of 0.7 mV per cycle with the voltage range of 2.1-4.6 V. This surface high-entropy strategy offers a universal approach to enhancing the redox stability of anions, contributing to the application of LMR.