Hydrothermal Synthesis of Tunable Olive-Like Ni0.8Co0.1Mn0.1CO3 and its Transformation to LiNi0.8Co0.1Mn0.1O2 Cathode Materials for Li-Ion Batteries

Uniform olive-like Ni0.8Co0.1Mn0.1CO3 carbonate precursors were successfully synthesized under hydrothermal conditions. Powder X-ray diffraction, field emission scanning electron microscopy, optical microscopy, and inductively coupled plasma optical emission spectroscopy revealed that crystal size and elemental contents of carbonate precursors could be slightly tuned by regulating the molar ratio of urea and transition metal ions, moreover, a synergetic crystal evolution mechanism involving Ostwald ripening and crystal etching for the formation of olive-like carbonate precursors was put forward for the first time. The improvement in temperature facilitated the increment in size of primary particles of oxides transformed from carbonate precursors. Vermiform LiNi0.8Co0.1Mn0.1O2 cathode materials transformed from olive-like carbonate precursors exhibited high discharge capacity of 193.4 mAh g(-1) at 0.2 C, and capacity retention of 85.4 % at 1 C after 100 cycles. Charge transfer impedance (R-ct) and diffusion coefficient of lithium ion (DLi+) revealed the electrochemical properties of cathode materials.