High-capacity positive electrode active material
This disclosure provides a positive electrode active lithium-excess metal oxide with composition Li x M y O 2 (0.6≦y≦0.85 and 0≦x+y≦2) for a lithium secondary battery with a high reversible capacity that is insensitive with respect to cation-disorder. The material exhibits a high capacity without the requirement of overcharge during the first cycles.
1. A lithium metal oxide characterized by a general formula Li x M y O 2 wherein 0.6≦y≦0.85, 0≦x+y≦2, and M being one or more of a metallic species chosen from the group consisting of Al, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Zr, Nb, Mo, Ru, Sn and Sb; wherein said oxide, as synthesized, has a random or partially random distribution of Li cations and M cations in the oxygen arrangement of the rock-salt structure, as measurable by XRD, wherein the lithium metal oxide has substoichiometric amount of lithium.
2. An electrode comprising a lithium metal oxide characterized by a general formula Li x M y O 2 wherein 0.6≦y≦0.85, 0≦x+y≦2, and M being one or more of a metallic species chosen from the group consisting of Al, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Zr, Nb, Mo, Ru, Sn and Sb; wherein said oxide, as synthesized, has a random or partially random distribution of Li cations and M cations in the oxygen arrangement of the rock-salt structure, as measurable by XRD.
3. A lithium battery comprising the electrode material of claim 2 .
4. A device comprising the lithium battery of claim 3 .
5. The device of claim 4 , wherein the device is a portable electronic device, an automobile, or an energy storage system.
6. A lithium-ion cell comprising the electrode material of claim 2 .