Abstract Herein, a Ketjenblack-coated Li[Ni1/3Co1/3Mn1/3]O2 cathode was characterized and compared with a pristine one. The polydopamine pre-coating layer was introduced to facilitate the adhesion between Ketjenblack and pristine powders. Homogenously dispersed Ketjenblack particles on the surface of the pristine powder indicated that the polydopamine layer acted as an effective binding agent. The discharge capacity, cyclic performance, and thermal stability of the Li[Ni1/3Co1/3Mn1/3]O2 cathode were improved by the polydopamine-assisted Ketjenblack coating. This implied that the Ketjenblack layer not only improved the electrical conductivity of the electrode but also protected the electrode from the reactive electrolyte.