Structure Determination of the Crystalline LiPON Model Structure Li(5+x )P(2)O(6−x )N(1+x ) with x≈0.9

Non‐crystalline lithium oxonitridophosphate (LiPON) is used as solid electrolyte in all‐solid‐state batteries. Crystalline lithium oxonitridophosphates are important model structures to retrieve analytical information that can be used to understand amorphous phases better. The new crystalline lithium oxonitridophosphate Li(5+x )P(2)O(6−x )N(1+x ) was synthesized as an off‐white powder by ampoule synthesis at 750–800 °C under Ar atmosphere. It crystallizes in the monoclinic space group P2(1)/c with a=15.13087(11) Å, b=9.70682(9) Å, c=8.88681(7) Å, and β=106.8653(8)°. Two P(O,N)(4) tetrahedra connected by an N atom form the structural motif [P(2)O(6−x )N(1+x )]((5+x)−). The structure was elucidated from X‐ray diffraction data and the model corroborated by NMR and infrared spectroscopy, and elemental analyses. Measurements of ionic conductivity show a total ionic conductivity of 6.8×10(−7) S cm(−1) at 75 °C with an activation energy of 0.52±0.01 eV.