A crystalline form of the oxynitride, Li2.88PO3.73N0.14, was prepared by solid-state reaction between Li3N and LiPO3 under flowing N2. The structure of the oxynitride was refined by the Rietveld analysis of neutron powder diffraction data, using the orthorhombic unit cell of -Li3PO4 (Pmnb). Liquid chromatography indicated that most of the N substituted for O so as to form PO3N structural units, with small concentrations of P-N=P due to some Li  P disorder. The ionic conductivity of the present material (10-13 S/cm) was several orders of magnitude higher than that of Li3PO4 (table 159).

B.Wang, B.C.Chakoumakos, B.C.Sales, B.S.Kwak, J.B.Bates: Journal of Solid State Chemistry, 1995, 115[2], 313-23

Table 159

Room-Temperature Conductivity and Activation Parameters

of Polycrystalline Lithium Oxynitride Materials