Solid solutions, Li(Fe, Co)xMn2 - xO4 (0 ≤ x ≤ 0.5 for Fe, 0 ≤ x ≤ 1.0 for Co) were synthesized by solid state reaction at 1023-1073 K in O2 atmosphere. The compositional dependence of lattice parameters and cation distribution was studied by neutron diffraction Rietveld refinement. It was revealed that Fe and Co partially occupied tetrahedral 8a sites and the 1:3 and 1:1 ordering did not occur on Fe (Co) and Mn ions in octahedral 16d sites. X-Ray absorption fine structure (XAFS) analysis showed the variation of valences and metal-oxygen interatomic distances of Mn, Fe, and Co. The Fe-O distance was longer whereas the Co-O distance was shorter compared to the averaged M16d-O32e distance calculated from the lattice parameters. Charge and discharge properties were studied in voltage range 3.0-5.3 V vs. Li/Li+.
All Science Journal Classification (ASJC) codes
- Materials Chemistry