Synthesis and electrochemical characterization of LiNi_(0.78)Co_(0.2)Al_(0.02)O_2 cathode material in a novel co-precipitation method

摘要

LiNi0.78Co0.2Al0.02O2 cathode materials were prepared with a novel co-precipitation method followed by heat-treating. The properties of the materials were characterized. XRD patterns showed that no secondary phase appeared and the hexagonal lattice parameter c of LiNi0.78Co0.2Al0.02O2 was larger than that of LiNi0.8Co0.2O2. The SEM images indicated that the powders of the material were submicron size. The results of the ICP-AES analysis proved that elemental compositions of the material were similar to those of the targeted one. Cyclic voltammetry (3.0-4.2 V) illustrated that the new material had good lithium-ion intercalation/de-intercalation performance. The results of galvanostatic cycling showed that the initial specific discharge capacity of the prepared material was 181.4 mAh/g, and the specific discharge capacity was 177.3 mAh/g after 100 cycles (0.2C, 3.0-4.2 V, vs. Li+/Li) with the capacity retention ratio of 97.7%.