Electrochemical Properties of Nanosized Li2MnO3·Li(Ni0.8Co0.15Al0.05)O2 Composite Cathode Powders

Nanometer-sized LiNi0.8Co0.15Al0.05O2 and 0.6Li2MnO3·0.4LiNi0.8Co0.15Al0.05O2 powders are prepared by high-temperature flame spray pyrolysis. The 0.6Li2MnO3·0.4LiNi0.8Co0.15Al0.05O2 composite powders post-treated at 700 and 800°C exhibit mixed-layer crystal structures comprising layered Li2MnO3 and layered LiNi0.8Co0.15Al0.05O2 phases. The mean sizes of the composite powders post-treated at 700 and 800°C are 127 and 180 nm, respectively. The layered–layered composite powders have sizes in the nanometer range with a slightly aggregated structure, whereas the layered LiNi0.8Co0.15Al0.05O2 powders have sizes in micrometer range with a hardly aggregated structure. The discharge capacity of the LiNi0.8Co0.15Al0.05O2 powders decreases from 163 to 95 mAh g-1 after 50 cycles with a capacity retention of 58%. The discharge capacity of the 0.6Li2MnO3·0.4LiNi0.8Co0.15Al0.05O2 composite powders decreases from 235 to 200 mAh g-1 after 50 cycles with a capacity retention of 85%