The enhancement of Hf~(4+) ion conduction in V-doped HfNb(PO_4)_3

摘要

The enhancement of tetravalent Hf~(4+) ion conduction was successfully realized by partially substituting the phosphorous (P) site in the NASICON-type HfNb(PO_4)_3 solid electrolyte with pentavalent vanadium cation to intentionally expand the crystal lattice size to make the Hf~(4+) ion migration easier. The V doping enhances the Hf~(4+) ion conductivity twice as high as that of pure HfNb(PO_4)_3. Here, the ratio of conducting ion size/crystal lattice volume has been demonstrated to be a suitable factor to design the optimization of the individual ion conduction in the NASICON-type structure.