Impacts of calcination temperature on the crystallography, granulometry and impedance of LiCoMnO\(₄\)

Spinel structured lithium cobalt manganese oxide (LiCoMnO4) which exhibit reduction potential surpassing 5.0 V (vs. Li0 | Li+) was identified to be one of the prospective cathode candidates for next generation lithium-ion electrochemical systems. This article highlights the significance of calcination temperature on the crystallography of the resultant electroceramic compound as well as the corresponding response on the granulometry and impedance of LiCoMnO4. LiCoMnO4 compounds synthesised via sol-gel reaction in the first instance were converted into xerogel and subsequently subjected to facile one-step calcination protocol. Crystallography of the post-calcinated compounds were characterised via powder x-ray diffraction (XRD) technique. Temperature ranging between 600℃ to 700℃ was identified to be the critical process window which enabled the formation of single phase LiCoMnO4. Granulometry of the LiCoMnO4 compound synthesised at 600℃ and 700℃ were characterised in term of morphology and particle size distribution. LiCoMnO4 calcinated at 600℃ attained smaller particle size distribution and renders in relatively lower charge transfer impedance as compared to the specimen subjected to calcination at 700℃ with relatively larger particle size distribution.