Surface modification of Li[Ni0.3Co0.4Mn0.3]O2 cathode by Li–La–Ti–O coating

A Li[Ni0.3Co0.4Mn0.3]O2 cathode is modified by applying a Li–La–Ti–O coating using the hydrothermal method. The coated Li[Ni0.3Co0.4Mn0.3]O2 is characterized by X-ray diffraction analysis, scanning electron microscopy, energy-dispersive spectrometry, transmission electron microscopy, and differential scanning calorimetry. The Li–La–Ti–O coating layer is formed as crystalline (perovskite structure) or amorphous phase depending on the heating temperature. The Li–La–Ti–O coated Li[Ni0.3Co0.4Mn0.3]O2 electrode has better rate capability than the pristine electrode. In particular, the rate capability is significantly associated with heating temperature; this is probably due to the phase of the coating layer. It appears that the Li–La–Ti–O coating of amorphous phase is superior to that of crystalline phase for obtaining enhanced rate capability of the coated samples. The thermal stability and cyclic performance of the Li[Ni0.3Co0.4Mn0.3]O2 electrode are also improved by Li–La–Ti–O coating. These improvements indicate that the Li–La–Ti–O coating is effective in suppressing the chemical and structural instabilities of Li[Ni0.3Co0.4Mn0.3]O2.