Synthesis and Characterization of Lithium Cobaltate and Lithium Manganese Oxides Nanopowders

Abstract

Lithium cobaltate LiCoO 2 and Li-Mn oxides nanopowders are synthesized by plasma chemical method in RF-IC plasma flow. Plasma forming gases are air or nitrogen, additionally air is used as oxidizing and quenching gas. As-synthesized and annealed in air nanopowders are investigated by powder XRD, BET, DTA/TGA, SEM, TEM methods and wet chemical analysis; lattice parameters are estimated by the programme SCANIX. Evaporation of initial powder mixtures Li 2 CO 3 +Co with Li/Co molar ratio 1:1 or Li 2 CO 3 +(Mn 2 O 3 +MnO 2 ) with various Li/Mn molar ratios, subsequent quenching and condensation of products results in obtaining of nanopowders with SSA of 13-23 m 2 /g and average particle size of 67-95 nm. After synthesis nanopowders contain admixtures of lithium nitrate hydrate LiNO 3 ·nH 2 O by-phase because of plasma flow composition and air environment. After heat-treating at 600-1000°C pure LiCoO 2 , LiMn 2 O 4 spinel, Li 2 MnO 3 , LiMn 2 O 4 +Li 2 MnO 3 are formed with good crystallinity and average particle size of 70-240 nm. Prepared nanopowders can be applied as cathode materials for Li-ion batteries with appropriate electrochemical properties for high discharge rate.