Progress in the modification of lithium-rich manganese-based layered cathode material

Developing the high energy density cathode materials for lithium ion batteries is the key to satisfy the demands of rapid development of electric vehicles and hybrid electric vehicles. Compared with traditional cathodes including LiCoO₂ and LiFePO₄, layered Li-rich Mn-based cathode materials are expected to achieve the index requirement of 300 W·h·kg^-1 because their specific capacity could reach up to 250 mA·h·g^-1 and the average discharge voltage exceeds 3.5 V. However, Li-rich materials have a poor cycle performance and gradual voltage decay during cycling, which is due to the irreversible phase transition from layered to spinel. In recent years, researchers have carries out tremendous works to solve these issues. In this paper, according to modification technology, the current studies including lattice doping, surface coating, designs of microstructure and control of active crystal plane are reviewed.