A Li[Ni0.4Co0.3Mn0.3]O2 cathode was modified by applying a La2/3−X Li3X TiO3 (LLT) coating. Transmission electron microscope (TEM) images reveal that the coating layer consists of nanoparticles. The coated cathode demonstrated an enhanced rate capability, discharge capacity, and cyclic performance than the uncoated cathode. However, the influence of the coating upon these electrochemical properties is highly dependent upon the composition of the LLT coating layer. Coating layers having high La and low Li contents, such as La0.67TiO3, effectively improved the rate capability of the cathode. However, coating layers with a low La and high Li content greatly enhanced the discharge capacity of the cathode under high cut-off voltage (4.8V) conditions. Overall, the thermal stability of the Li[Ni0.4Co0.3Mn0.3]O2 electrode was improved by the LLT coating. Storage tests confirmed that the La2/3−X Li3X TiO3 coating dramatically suppressed the dissolution of transition metals into the electrolyte.