Structural characteristics of olivine Li(Mg0.5Ni0.5)PO4 via TEM analysis

The structural characteristics of olivine-type lithium orthophosphate Li(Mg 0.5Ni 0.5)PO 4 synthesized via solid-state reaction have been studied using X-ray diffraction, ion beam technique, scanning electron microscopy, infrared spectroscopy, transmission electron microscopy and energy dispersive X-ray analysis. The parent LiNiPO 4 compound can be synthesized in olivine structure without any evidence of secondary phases as impurities. The structural quality of the parent LiNiPO 4 in the absence of secondary component phases resulted in the formation of hexagonal closed packed structure. The olivine analogue compound containing mixed M (M = Mg, Ni) cations, Li(Mg 0.5Ni 0.5)PO 4 contained Li 3PO 4 as a second phase upon synthesis, however a carbothermal reduction method produced a single-phase compound. The redox behaviour of carbon-coated Li(Mg 0.5Ni 0.5)PO 4 cathode in aqueous lithium hydroxide as the electrolyte showed reversible lithium intercalation