Effects of Co3(PO4)2 coatings on LiNi0.8Co0.16Al0.04O2 cathodes during application of high current

The electrochemical properties of bare and Co-3(PO4)(2)-coated LiNi0.8Co0.16Al0.04O2 electrodes after high current damage testing were characterized. Damage was induced by cycling with a high current density of 600 m Ag(-1)supercript stop. Co-3(PO4)(2)-coated LiNi0.8Co0.16Al0.04O2 electrodes exhibit lower capacity loss and better charge retention than bare LiNi0.8Co0.16Al0.04O2 electrodes after damage testing. The discharge capacity reduction of bare and Co-3(PO4)(2)-coated electrodes after damage testing were similar to 27 and 15%, respectively. The impedance of cells containing bare electrodes remarkably increased after high current cycling, which may be induced by damage to the electrode surface. However, damage was successfully suppressed by the Co-3(PO4)(2) coating. Bare LiNi0.8Co0.16Al0.04O2 electrodes developed large amounts of cracks and other extended defects after high current cycling. In contrast, Co-3(PO4)(2)-coated electrodes maintained stable features after high current cycling, indicating the coating layer effectively protected the surface of the LiNi0.8Co0.16Al0.04O2 powder.