Review-Recent Advances On High-Capacity Li Ion-Rich Layered Manganese Oxide Cathodes

Lithium rich manganese oxides (LRMOs) for lithium ion battery cathode applications have generated worldwide interest due to the low cost of manganese owing to its high abundance, their high theoretical capacities as well as the low toxicity of the materials. Amongst the LMRO family, Li2MnO3 (Li[Li0.33Mn0.67]O-2) once thought to be electrochemically inactive, has emerged as a superior candidate for high capacity cathode material application in electric vehicles and grid storage due to exceptional theoretical capacities which are as high as 459 mAh g(-1). However, this material suffers from low initial coulombic efficiencies, capacity fading during cycling and low rate capacities. Herein, we report on various advances that have been made in addressing the above-mentioned drawbacks by suppressing lattice oxygen loss and phase transformations which lead to the poor performance. We will review surface modifications on these materials and their implication in the improvements of LMROs. Finally, we will give an overview of what the future looks like for such materials.