LiNi0.8Al0.2O2 with a higher Ni3+/Li+ ordering, synthesized by the solution-combustion method, gives oxygen-evolution-reaction (OER) activity in alkaline solution that is comparable to that of IrO2. This confirms that the octahedral-site Ni-IV/Ni-III couple in an oxide is an active redox center for the OER with redox energy pinned at the top of the O-2p bands.