Solution Combustion Synthesis of Lithium Cobalt Oxide – Cathode Material for Lithium-Ion Batteries

摘要

A simple but novel solution combustion synthesis (SCS) technique suitable for LiCoO2 scaleproduction was developed. Citric acid was used together with glycine to slow down the combustionrate; cobalt(II) nitrate was partially replaced with cobalt(II) carbonate hydroxide to reduce the heatingof the off-gases using the excess heat of the redox reaction. As a result, no open flame or eruption ofthe powder product out of the reactor was observed; the rapid SCS process occurring in the desirednon-turbulent mode is suitable for scaling. The influence of the ratios cobalt(II) nitrate/cobalt(II)carbonate hydroxide and glycine/citric acid on the LiCoO2 powder product properties was examinedalong with the influence of the post-combustion annealing conditions and pH of the precursor solution.The thus-obtained LiCoO2 powders were characterised by X-ray diffraction, scanning electronmicroscopy and particle size distribution analysis. Testing of the electrochemical behaviour of theLiCoO2 powders was performed in Li/LiCoO2test cells having 1M LiDFOB in EC/DMC (1:1, wt.) asan electrolyte. The results confirmed the high electrochemical activity of the SCS-derivedLiCoO2powders; the best samples exhibited a discharge capacity ≥150 mAh g-1 and coulombicefficiency ≥99.5 % following 30 cycles at C/10 rate.