Resolving the structure of V 3 O 7 ·H 2 O and Mo-substituted V 3 O 7 ·H 2 O.

Vanadate compounds, such as V 3 O 7 ·H 2 O, are of high interest due to their versatile applications as electrode material for metal-ion batteries. In particular, V 3 O 7 ·H 2 O can insert different ions such as Li + , Na + , K + , Mg 2+ and Zn 2+ . In that case, well resolved crystal structure data, such as crystal unit-cell parameters and atom positions, are needed in order to determine the structural information of the inserted ions in the V 3 O 7 ·H 2 O structure. In this work, fundamental crystallographic parameters, i.e. atomic displacement parameters, are determined for the atoms in the V 3 O 7 ·H 2 O structure. Furthermore, vanadium ions were substituted by molybdenum in the V 3 O 7 ·H 2 O structure [(V 2.85 Mo 0.15 )O 7 ·H 2 O] and the crystallographic positions of the molybdenum ions and their oxidation state are elucidated.