A ternary oxide precursor with trigonal structure for synthesis of LiNi0.80Co0.15Al0.05O2 cathode material

Abstract

A Ni-Co-Al ternary oxide precursor with a trigonal structure, which can be used to synthesize LiNi0.8Co0.15Al0.05O2 cathode material, was prepared by calcining Ni-Co-Al composite oxalates formed by using a facile chemical approach. The LiNi0.8Co0.15Al0.05O2 cathode material calcined at a temperature as low as 650 °C had acceptable electrochemical performance with an initial discharge capacity of 183.9 mAh g−1. The sample prepared at 750 °C possessed the highest initial discharge capacity of 196.0 mAh g−1, while the sample calcined at 700 °C showed the optimal capacity retention (89.9%) after 100 cycles under 1 C. To prepare a pure LiNi0.8Co0.15Al0.05O2 phase by a conventional solid-state reaction, the calcination temperature should exceed 750 °C, and the highest initial discharge capacity was only 185.4 mAh g−1. We suggest that the ternary oxide precursor with trigonal structure accelerates lithiation and, therefore, promotes the generation of LiNi0.8Co0.15Al0.05O2 with high crystallinity at a lower temperature. This study provides a facile way to synthesize layered cathode material with good electrochemical performance at a lower calcination temperature.