Effect of precipitators on the morphologies and electrochemical properties of Li1.2Mn0.54Ni0.13Co0.13O2 via rapid nucleation and post-solvothermal method

Abstract Different morphologies of Li-rich layered oxides, Li 1.2 Mn 0.54 Co 0.13 Ni 0.13 O 2 (LMNCO), were synthesised using a rapid nucleation and post-solvothermal method followed by calcination. After the process of rapid nucleation, the as-prepared mixture of M(OH) 2 using NaOH as the precipitator showed nanoplate aggregation, while the mixture of MCO 3 using (NH 4 ) 2 CO 3 as the precipitator presented a spherical morphology. After subsequent solvothermal processing and calcination, Li 1.2 Mn 0.54 Co 0.13 Ni 0.13 O 2 samples with uniform nanoplate particles (LMNCO-P) and spherical particles (LMNCO-S) were obtained. The as-prepared LMNCO-P and LMNCO-S samples exhibited excellent electrochemical performance and delivered high initial discharge capacities of 282 and 278 mA h g −1 , respectively, at 0.1C with a cut-off voltage in the range 2.0–4.8 V. The LMNCO-S cathode material exhibited outstanding cycling performance with capacity retention ratios of 88%, 89%, and 92% at 1, 2, and 5C, respectively, after 100 cycles. Furthermore, after a stepped pre-cycling treatment, the capacity retention of the LMNCO-S cathode material reached 79% after 500 cycles at 5C. The superior cycling performance can be ascribed to the spherical morphology with a small surface area, which decreased side reactions with the electrolyte and enhanced the crystal structure stability after the pre-cycling treatment.