Li-Rich Manganese-Based Cathodes for Lithium-Ion Batteries

High-energy-density lithium-ion batteries have been in high demand and this has led to a lot of research on the advanced cathode materials. Li-Rich Manganese-Based Cathodes are also a promising candidate due to their ultrahigh reversible capacity, which is attributed to the co-participation of transition-metal cations and lattice oxygen anions in charge compensation, as well as low cost and rich manganese resources. Nonetheless, there are three inherent difficulties that greatly impede their practical application: low initial Coulombic efficiency due to irreversible oxygen release during first activation, severe voltage decay caused by layered-to-spinel phase transformation during cycling, and poor interfacial stability due to electrolyte oxidative decomposition and resistive cathode electrolyte interphase formation at high operating voltages. To solve these problems, three mainstream modification approaches have been developed simultaneously: element doping targets bulk structural degradation via lattice stabilization and oxygen release suppression and transition-metal migration; surface coating with inert layers like Al 2 O 3 , TiO 2 , phosphate, fluoride etc. operates at the electrode-electrolyte interface to physically prevent side reactions; electrolyte additives control in-situ CEI formation to stabilize interfacial layer. It is stressed here that only simultaneous inhibition of oxygen release, phase transformation and high-voltage interfacial side reactions can convert the inherent capacity advantage of Li-Rich Manganese-Based Cathodes into practical energy density. Future works should focus on coupled bulk and interfacial regulation strategies, followed by systematic full-cell validation to promote their practical application.