Fabrication of nanoplate Li-rich cathode material via surfactant-assisted hydrothermal method for lithium-ion batteries

Abstract

A Li-rich cathode material Li[Li0.2Ni0.2Mn0.6]O2 is obtained via a facile hydrothermal treatment combined with post-sintering lithiation using cetyltrimethylammonium bromide (CTAB), polyvinyl pyrrolidone (PVP), or sodium dodecyl benzene sulfonate (SDBS) as a surfactant. The prepared materials are characterized in detail using X-ray diffraction, scanning electron microscopy, transmission electron microscopy, and energy-dispersive X-ray spectroscopy. Among all samples, Li[Li0.2Ni0.2Mn0.6]O2 (C-LLNMO), with the assistance of CTAB, possesses the smallest particle size and the most uniform distribution, which is mainly due to the preferential adsorption and electrostatic repulsion of CTAB during hydrothermal treatment. Benefiting from these microstructural advantages, the C-LLNMO cathode exhibits the highest specific discharge capacity of 270 mAh g−1 at 0.1 C. Meanwhile, C-LLNMO displays excellent electrochemical stability, with a capacity retention of 89.5% at 1 C after 200 cycles, and a high rate capability reaching 149.2 mAh g−1 at a charge-discharge rate of 5 C. The fundamental cause of this enhanced electrochemical performance is the regulation of the structure and morphology of Li-rich materials using CTAB during the hydrothermal process