Novel solution-combustion synthesis of LiCoO2 and its characterization as cathode material for lithium-ion cells

Lithium cobalt oxide (UCoO2) which is being widely used as cathode material in lithium-ion batteries is synthesized by a novel solution-combustion procedure. In this synthesis, a solution mixture Of CO(NO3)(2), Li2CO3 and diformyl hydrazine fuel is heated to ignite at 350 degreesC. This is accompanied by decomposition of cobalt nitrate and lithium carbonate to form LiCoO2 within a few minutes, which is annealed at 850 degreesC for 6 h to obtain an ordered-crystalline layered compound. The powder X-ray diffraction pattern of the prepared LiCoO2 shows a hexagonal cell with a = 2.81 and c = 13.83 Angstrom. Electrodes made with LiCoO2, acetylene black and poly(vinyledene fluoride) yield a discharge capacity of similar to 120 mAh g(-1) with good Faradaic efficiency over several charge-discharge cycles. Cyclic voltammetric and ac impedance data also corroborate the electrochemical activity of LiCoO2 synthesized in the present study. (C) 2001 Elsevier Science B.V. All rights reserved.