Abstract Title   High Energy Density Cathodes for Next Generation Lithium Ion Batteries Abstract Author(s)   Arumugam Manthiram Materials Science and Engineering Program The University of Texas at Austin Austin, TX 78712 Abstract Presenter   Arumugam Manthiram Abstract   The structural and chemical instabilities arising from an overlap of the Co3+/4+:3d band with the top of the O2-:2p band limit the practical capacity of the currently used layered LiCoO2 cathode to 50 % of its theoretical capacity. Moreover, LiCoO2 suffers from high cost, toxicity, limited power capability, and safety concerns. These difficulties have created enormous interest in the development of alternative cathodes for next generation lithium ion batteries. In this regard, solid solutions between layered Li[Li1/3Mn2/3]O2 and layered Li[M]O2 (M = Ni1-y-zMnyCoz) have become appealing as they exhibit two times higher capacity than LiCoO2 while lowering the cost and improving the safety. However, these layered oxide solid solutions exhibit an irreversible loss of oxygen from the lattice during first charge and a huge irreversible capacity loss in the first cycle. They also suffer from low rate capability. This presentation, after first focusing on the factors influencing the discharge capacity and irreversible capacity values, will concentrate on reducing the irreversible capacity loss, increasing the discharge capacity, and improving the rate capability. Specifically, optimization of the synthesis processes to improve the electrochemical performance parameters, surface modification with other oxides like Al2O3 and AlPO4 to reduce the irreversible capacity loss and increase the rate capability, and mixing with lithium-free insertion hosts like V2O5 to eliminate the irreversible capacity loss will be presented. Optimized compositions that exhibit capacities close to 300 mAh/g with high rate capability will be presented.