Review-Recent Advances and Remaining Challenges for Lithium Ion Battery Cathodes: II. Lithium-Rich, xLi⊂2⊆MnO⊂3⊆(1-x)LiNi⊂a⊆Co⊂b⊆Mn⊂c⊆O⊂2⊆

Electrodes prepared from lithium-rich (Li-rich) xLi(2)MnO(3) center dot (1-x) LiNiaCobMncO2 materials (a + b + c = 1) show extremely high discharge capacities, arising from excess Li+ present in their Li2MnO3 component, and the ability to reversibly store charge with O2- anions. These electrodes suffer serious voltage and capacity fading however, due to the migration of transition metals to the Li-layer at advanced states of charging, partial structural layered-to-spinel transformation and other reasons. In this focus paper, the current understanding of the above materials is summarized, briefly concluding with attempts by our groups to mitigate the voltage and capacity fade of these electrodes. (C) The Author(s) 2017. Published by ECS. All rights reserved.