Electrochemical Properties of High Nickel Content Li(Ni0.7Co0.2Mn0.1)O2 with an Alumina Thin-Coating Layer as a Cathode Material for Lithium Ion Batteries.

The cathode material, high Nickel content Ni0.7Co0.2Mn0.1 (NCM), was synthesized by coprecipitation with NH4OH used as a complexing agent. The prepared materials are made in the formation of spherical particles of Li(Ni0.7Co0.2Mn0.1)O2 of several micrometers in diameter. Al2O3 was coated by an impregnation method and its content was gradually increased to 1, 2 and 5 wt%. As a result, 1 wt% coated Al2O3 compared to pristine NCM exhibited 82% and 80% retention rates at 5 C and 1 wt% Al2O3 coated NCM recovery at 0.2 C after 5 C showed 100%. In addition, capacity retention of 1 wt% NCM+Al gently decreased in 100 cycle life characteristics, and capacity retention of 95% or more was confirmed.