Effect of carbon coating on improved electrical and electrochemical performance of Li₃Co₂SbO₆

Abstract

We reported a novel high voltage cathode having layered structure and manifold improvement
(144 %) in electrochemical performance on carbon coating Li3Co2SbO6. The carbon-coated
Li3Co2SbO6 has been prepared using a high temperature solid-state method in an air medium
with appropriate stoichiometry of the oxide and carbon source (sucrose). The X-ray diffraction
and high-resolution transmission electron microscopy results have confirmed homogeneous
carbon coating on oxide (Li3Co2SbO6) surface without disturbing phase, structure and
morphology. The immediate effect of carbon coating resulted in electrical conductivity
enhancement of the carbon coated Li3Co2SbO6 four order of magnitudes ~ 2.79 × 10-4 Scm-1 at
room temperature vis-a-vis pristine Li3Co2SbO6. The electrochemical performance of the
carbon coated Li3Co2SbO6 has shown sustainable improvement indicating redox activity by
more than one Li+. The carbon coated Li3Co2SbO6 cathode exhibited an initial discharge
capacity of 110 mAhg-1 compared to 45 mAhg-1 for pristine counterpart. The improvement in
electrochemical capacity on carbon coating in this work, is the highest ever compared to
literature reports on Li3Co2SbO6.