Influence of LiMn₂O₄ modification with CeO₂ on electrode performance

Highlights: • We successfully modified LiMn₂O₄ surface using 1%wt. CeO₂. • CeO₂ - modified sample reveals better high rate performance in comparison with pristine LMO. • LMO/CeO₂ reveals excellent capacity retention with barely 2% of capacity loss after 100 of charge/discharge cycles. • The micro-Raman mapping images determined the distribution of CeO₂ particles in the sample. - Abstract: In this article we present a low temperature method applied to modify the surface of lithium manganese oxide grains' by using cerium dioxide. In order to determine the structure, size of particles and morphology of the pristine and surface modified LiMn₂O₄ powders we used several complementary methods: X-ray powder diffraction (XRD), scanning electron microscope (SEM), transmission electron microscope (TEM) and Raman spectroscopy. The galvanostatic charge/discharge tests of the pristine and CeO₂ modified LiMn₂O₄ cathode materials were conducted in the potential range: 3.5 to 4.5 V vs. Li/Li⁺ at room temperature. High current rates performance has been evaluated by determination of specific discharge capacity at current rates varied from 1 C to 30 C. Our work demonstrates that surface modification of LiMn₂O₄ grains' by using 1%wt. of cerium dioxide admixture improves cycling stability and capacity retention. Pristine LMO reveals 10% capacity loss after 100 cycles when discharged at 1 C, while the sample modified with CeO₂ grains reveals only ca. 2% capacity loss