This study examined the electrochemical and structural stability of ∼1.5wt.% AlPO 4 -coated LiNi 0.9 Co 0.1 O 2 . The AlPO 4 -coated LiNi 0.9 Co 0.1 O 2 retained ∼60% of the original capacity after 50 cycles, compared with the ∼30% capacity retention of the bare LiNi 0.9 Co 0.1 O 2 . The discharge profiles and cyclic voltammograms from 4.5V at 90°C for 4h showed enhanced structural stability. Scanning electron microscopy and X-ray diffraction revealed that the AlPO 4 -coated LiNi 0.9 Co 0.1 O 2 had less degradation than the bare LiNi 0.9 Co 0.1 O 2 .