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

Minakshi, M., Singh, P., Ralph, D., Appadoo, D., Blackford, M. and Ionescu, M. (2012) Structural characteristics of olivine Li(Mg0.5Ni0.5)PO4 via TEM analysis. Ionics, 18 (6). pp. 583-590.

Abstract

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.