Divalent Sr2+ cation conducting solid electrolyte with NASICON-type structure

Abstract

A divalent strontium cation highly conducting solid was successfully developed by introducing Sr2+ cations into the NASICON-type HfNb(PO4)3 solid together with W6+ ions. The (Sr0.05Hf0.95)4/3.9(Nb1-yWy)5/(5+y)(PO4)3 solid exhibited Sr2+ conductivity that was 3300 times higher than that of previously reported NASICON-type Sr2+ conductors, which was caused by the effective reduction of electrostatic interaction between conducting Sr2+ and surrounding O2- ions due to the existence of high valent Nb5+ and W6+ cations in the structure.