Lithium-Reactive Co[sub 3](PO[sub 4])[sub 2] Nanoparticle Coating on High-Capacity LiNi[sub 0.8]Co[sub 0.16]Al[sub 0.04]O[sub 2] Cathode Material for Lithium Rechargeable Batteries

Metal ion dissolution from high-capacity cathode material during storage at 90°C was completely blocked by a lithium-reactive nanoparticle coating. As opposed to conventional coating methods, in which the coating material did not react with and impurities dissolved from the cathode, the coating material reacted with such impurities during annealing to form an olivine phase on the bulk surface. Electrochemical properties of the optimized sample, annealed at 700°C for , demonstrated a 30% enhancement of the cycle life, compared to a bare sample without a loss in the first discharge capacity. Storage tests of the charged electrode at 90°C after 7 days showed that the bare sample was transformed into the spinel phase with a space group, whereas the -coated sample remained as a layered hexagonal phase with an space group.