Li2MnO3-based composite cathodes for lithium batteries: A novel synthesis approach and new structures
A new, simple technique has been demonstrated for fabricating high-capacity composite electrode structures. In this technique, Li 2 MnO 3 is leached in acid in the presence of soluble transition metal ions and subsequently annealed between 450 and 850°C. The technique can be used to prepare a wide variety of composite compounds, in particular, a new family of 'layered-rocksalt' xLi 2 MnO 3 ·(1−x)MO (e.g., M = Ni and Co) structures and modifications thereof, as well as 'layered-layered' xLi 2
... d-layered' xLi 2 MnO 3 ·(1−x)LiMO 2 (e.g., M = Mn, Ni, and Co) and 'layeredspinel' xLi 2 MnO 3 ·(1−x)LiM 2 O 4 (e.g., M = Mn and Ni). This novel approach also holds promise for 1) synthesizing materials that reduce the extent of internal phase transitions of composite cathode structures with a high manganese content, and 2) minimizing the extent to which cells need to be electrochemically activated to remove Li 2 O, thereby reducing the extent of the irreversible capacity loss on the first charge/discharge cycle.