Synthesis and electrochemical properties of spinel LiCo1/6Mn11/6O4 powders by a spray-drying method

Co-substituted LiCo1/6Mn11/6O4 powders were prepared by a spray-drying method for positive electrodes of lithium ion batteries. The heat treating process, crystal structure and electrochemical properties of the synthesized materials were investigated by TG/DTG, DSC, XRD, SEM, slow rate cyclic voltammetry (CV) and galvanostatic charge/discharge cycling tests. The final powders were identified as single-phase spinel LiCo1/6Mn11/6O4 with high degree of crystallization and uniform particle size distribution. In the charge/discharge potential (versus Li/Li+) ranging from 2.0 to 4.4 V, the LiCo1/6Mn11/6O4 electrode delivered high initial discharge capacity of 242 mAh g-1 at 1/10 C rate at 25 deg. C. In the potential range of 3.5-4.4 V, it showed high discharge capacity and excellent cycling performance at 1/5, 1/2, 1 C rate at 25 deg. C and 55 deg. C. The improvement in cycling performance might be contributed by the stabilization of spinel structure by smaller lattice constant when manganese ion was partially substituted by Co3+ ion. The spray-drying method is an effective method to prepare co-substituted lithium manganese oxide within very short production time, and thus is promising for commercial application