High energy density Li2MnO3 (layered)–LiMn1.5Ni0.5O4 (spinel) composite cathodes have been synthesized using auto-combustion route. Rietveld refinements together with the analyses of high resolution transmission electron micrographs confirm the structural integration of Li2MnO3 nano-domains into the LiMn1.5Ni0.5O4 matrix of the composite cathodes. The discharge capacity of the composite cathodes are due to the intercalation of Li+ ion in the tetrahedral (8a) and octahedral (16c) sites of the spinel component and also the insertion of Li+ in the freshly prepared MnO2 lattice, formed after Li2O extraction from the Li2MnO3 domains. The capacity fading of the composite cathodes are explained to be due to the layered to spinel transition of the Li2MnO3 component and Li+ insertion into the octahedral site of the spinel lattices which trigger cubic to tetragonal phase transition resulting volume expansion which eventually retard the Li+ intercalation with cycling.
|Number of pages||9|
|Journal||Materials Science and Engineering B: Solid-State Materials for Advanced Technology|
|State||Published - 1 Nov 2016|