Synthesis and structural features of spinel-type nanomaterials AMn2O4(A = Co, Zn, Ni, Cd, Cu)

Bijelić, Mirjana (2016) Synthesis and structural features of spinel-type nanomaterials AMn2O4(A = Co, Zn, Ni, Cd, Cu). Doctoral thesis, Faculty of Science > Department of Chemistry.

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Abstract

Structural studies on AMn2O4 (A = Co, Zn, Ni, Cd, Cu) have been performed in order to determine the influence of the synthesis conditions on the specific features of spinel structure, primarily on the inversion parameter. It was found that all samples belong to the spinel structure type; CoMn2O4, ZnMn2O4 and CdMn2O4 are tetragonal while NiMn2O4 and CuMn2O4 crystallize in the cubic system. The inversion parameter of CoMn2O4 and CdMn2O4 increases with increasing temperature (25500 °C) while inversion in ZnMn2O4 increases with increase of temperature up to 300 °C and decreases afterwards. Structure of NiMn2O4 does not depend on the heat treatment. Phase purity for CuMn2O4 was not achieved regardless of the temperature of the heat treatment. Electrochemical measurements were carried out for all samples; CoMn2O4 showed the best electrochemical performance. The increase in heat treatment caused pronounced particle growth. The sample with the largest particle size showed the highest specific capacity, best electrochemical cycling and extremely high capacity retention (104 % after 1000 cycles).

Item Type: Thesis (Doctoral thesis)
Keywords: inversion, litium-ion battery, spinels, X-ray powder diffraction
Supervisor: Popović, Jasminka
Date: 2016
Number of Pages: 134
Subjects: NATURAL SCIENCES > Chemistry
Divisions: Faculty of Science > Department of Chemistry
Depositing User: Branka Maravic
Date Deposited: 22 Mar 2016 16:05
Last Modified: 22 Mar 2016 16:08
URI: http://digre.pmf.unizg.hr/id/eprint/4596

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