Various types of trivalent SC3+ cation conducting solid electrolytes of the
(Sc1-xAlx)(1/3)Zr-2(PO4)(3) (0 less than or equal tox less than or equal t
o0.6), the Sc-1/3(Zr1-yHfy)(2)(PO4)(3) (0 less than or equal toy <1) and th
e (Sc0.8Y0.2)(1/3)Zr-2(PO4)(3) solid solutions were prepared and the Sc3+ i
on conducting properties were compared. The optimum SC3+ ion conductivity i
n NASICON type solid electrolytes was successfully obtained for the (SC0.8A
l0.2)(1/3)Zr-2(PO4)(3) and the Sc-1/3(Zr0.8Hf0.2)(2)(PO4)(3) solids, holdin
g almost the equivalent NASICON crystal lattice size, and the optimization
of the Sc3+ ion conduction in NASICON structure was realized.