Synthesis of lithium nickel cobalt manganese oxide Nano powder by ultrasonicspray pyrolysis as cathode active material of lithium ion battery

Nowadays, lithium ion batteries (LIBs) have special situation in portable electronics market andwidespread researches have carried out in a various fields of LIBs such as cost reduction,preventing environmental damages, and improving performance. The main components of a LIBare anode, cathode, electrolyte and separator, among which the cathode material is a limitingfactor in terms of both cost and performance [1]. The first cathode material for commercial LIBwas lithium cobalt oxide (LCO) which has problems like cobalt resource constraints, high cost,toxicity, and low safety, and these problems has limited use of LCO in high power batteries ofelectric and hybrid electric vehicles [2]. Therefore researchers are looking for alternatives, forwhich their LiNixCoyMn1-x-yO2 (NCM) compositions are one of the candidates owing to havehigher capacity, lower cost and better thermal stability than LCO [3]. This work focused onsynthesis of lithium nickel cobalt manganese oxide using ultrasonic spray pyrolysis. This methodproduces high purity material, easily control properties of product, and have low cost comparedto other conventional synthesis methods including solid state, sol-gel and co-precipitation [4].The effect of concentration of precursor solution on morphology and particle size, effect ofsynthesis temperature and calcination temperature on morphology, structure, and capacity wereinvestigated. Crystal structure of LiNi0.4Co0.2Mn0.4O2 powder was studied by X-ray diffraction(XRD), and all patterns indicated ordered layered structure. Scanning electron microscopic(SEM) images showed micron-sized spherical particles composed of nanoparticles. Initial chargecapacity of LiNi0.4Co0.2Mn0.4O2 as cathode material in voltage range of 2.5-4.4V reached to124mAh/g, for the sample synthesized in 600ºC and calcinated in 850ºC. The coulombic efficiencyand capacity retention after 10 charge-discharge cycles were 90% and 80% respectively.

Keywords:

Lithium ion battery , Cathode active material , Lithium nickel cobalt manganese oxide , Ultrasonic spray pyrolysis