Synthesis of LiNi_1/3Co_1/3Mn_1/3O₂ Composite Powders by Solid State Reaction

Abstract

A mixture of Li2CO3, NiO, Co2O3 and MnO2 with a molar ratio was introduced in the mixed high energy ball milling, LiNi1/3Co1/3Mn1/3O2 was prepared by solid state phase using mechanochemical activation which has highly reactive materials. The structure and electrochemical properties of LiNi1/3Co1/3Mn1/3O2 were analisised by employing X-ray diffraction(XRD), scanning electron microscopy(SEM) and galvanotactic charge-discharge test. Charge-discharge test results show that when the the LiNi1/3Co1/3Mn1/3O2 cathode was prepared by wet milling 10h between 2.8 V and 4.4V at a current of 0.5C rate, the initial discharge capacity is 135.1mAh/g, the capacity retention rate of 93.26% after 20 cycles. When nLi: n (Ni + Co + Mn) = 1.1, the samples sintered 20h at 850 °C, the first discharge capacity is 148.5 mAh/g, and the capacity retention rate is 94.88% after 40 cycles.

Synthesis of Alkali Transition Metal Oxides Derived from Prussian Blue Analogues Toward Low Cationic Disorder for Li-Ion Battery Cathodes

“…However, the NCM suffers from notable drawbacks as follows: (1) a relatively low electrical conductivity, (2) a cation mixing between the Li + ion (0.76 Å) and Ni 2+ ion (0.69 Å) that deteriorates Li + ion diffusivity and lithium storage properties, (3) an irreversible hexagonal phase transition from H1 (an initial hexagonal phase) to H2 (a second hexagonal phase with a larger c lattice constant) or H3 (a third hexagonal phase with a smaller c lattice constant) when Li + ions are de-intercalated below 0.3 in the LiNi x Co y Mn z O 2 . Regarding the preparation of NCM, various methods have been developed including solid-state reaction, (co)­precipitation, spray-drying, sol–gel, hydrothermal reaction, microemulsion, carbonate process, thermal polymerization, etc. It is important to choose synthetic methods and conditions because they have a great influence on particle size, morphology, surface condition, phase purity, crystallite, etc.…”