Synthesis and Rechargeable Properties of LiNi_0.5Mn_1.5O₄ Cathode Materials by Spray Pyrolysis

Abstract

Spinel type of LiNi_0.5Mn_1.5O₄ cathode materials were continuously prepared by two-fluid type of spray pyrolysis. As-prepared powders had spherical morphology with porous microstructure which had an average diameter of 3.7 μm with broad size distribution. The particle morphology of LiNi_0.5Mn_1.5O₄ powders was influenced by the calcination and the polygonal morphology was obtained at 1000°C. XRD showed that LiNi_0.5Mn_1.5O₄ was well crystallized after the calcination at 700°C. The electrochemical measurement of LiNi_0.5Mn_1.5O₄ cathode showed that the long plateau was observed at 4.7 V in rechargeable curve of LiNi_0.5Mn_1.5O₄ cathode and its discharge capacity was 145 mAh/g at 1 C. The capacity retention of LiNi_0.5Mn_1.5O₄ cathode was 95 % at 1 C after 100 cycles. The discharge capacity and capacity retention of LiNi_0.5Mn_1.5O₄ cathode was 125 mAh/g and 88 % at 20 C, respectively. LiNi_0.5Mn_1.5O₄ cathode exhibited also stable cycle performance at 50°C.