Effects of Atomic Layer Deposition of Al2O3 on the Li[Li0.20Mn0.54Ni0.13Co0.13]O2 Cathode for Lithium-Ion Batteries

The lithium-excess layered oxide Li[Li 0.2 Mn 0.54 Ni 0.13 Co 0.13 ]O 2 has been surface modified with Al 2 O 3 films grown with atomic layer deposition (ALD) and examined as cathodes for lithium-ion batteries. Al 2 O 3 was grown on powders prior to electrode fabrication, directly on the electrode, and directly on the electrode followed by a heat-treatment at 300°C in air. Compared to the bare electrode, an Al 2 O 3 film on an as-formed electrode improved the cycle performance significantly. Furthermore, the heat treatment of the ALD-coated electrodes result in significant increase in capacity, due to the transformation of the as-deposited Al 2 O 3 to a better Li + -conductive material. X-ray photoelectron spectroscopy (XPS) results indicate that the heat-treatment leads to an inter-diffusion of atoms between the Al 2 O 3 coating and the Li[Li 0.20 Mn 0.54 Ni 0.13 Co 0.13 ]O 2 core.