LiNi0.5Co0.2Mn0.3O2 hollow microspheres-synthesis, characterization and application as cathode materials for power lithium ion batteries

LiNi0.5Co0.2Mn0.3O2 (T-NCM) cathode material with hollow microsphere structure is synthesized by binary template method. The microspheres with diameters of about 2.5 μm and hollow interior structure with walls thickness of approximately 0.8 μm. When tested by half-cells, T-NCM material exhibits better electrochemical performances than LiNi0.5Co0.2Mn0.3O2 (C-NCM) material prepared by co-precipitation method. Specifically, T-NCM sample delivers discharge capacities of 180.3, 148.5 and 127.8 mAh g− 1 at 0.2C, 5C and 10C rates between 3.0 and 4.3 V, respectively. After 100 cycles, capacity retention ratios at 0.2C and 5C are 86.58% and 82.63%, respectively. In addition, application property of the as-synthesized materials is evaluated by the fabrication of 18650 full batteries. The 18650 battery assembled with T-NCM material as the cathode achieves discharge capacities of 2138.8, 1870.2, and 1652.2 mAh at 0.5C, 5C and 10C rates under the voltage range of 2.75-4.2 V, respectively, with capacity retention rate maintained as high as 96.30% after 500 cycles at current of 2 A (1C), which are superior to that of 18650 battery fabricated with C-NCM as the cathode. The better processability of T-NCM is ascribed to the more uniform particle size distribution and smaller particle size. The excellent electrochemical performances of T-NCM electrode in half-cells and 18650 full batteries can be attributed to the unique hollow microspheres structure. This work illustrates that the T-NCM material is a promising candidate as cathode material for power lithium ion batteries.