The First Combined Experimental and Theoretical Evaluation of Tetravalent Cation Conduction in a Solid

Abstract Tetravalent tellurium ion conduction in solids has been demonstrated in α‐Te 2 MoO 7 by both experimental and theoretical means for the first time. Although it has been commonly considered that the Te 4+ ion will not conduct appreciably in solids due to its high valency, such conduction can be successfully achieved in solid α‐Te 2 MoO 7 , which has a 2D layered structure conducive to ion migration. The measured Te 4+ ion conductivity in solid α‐Te 2 MoO 7 (1.0 × 10 –2 S cm –1 at 530 °C) reaches the threshold required for practical applications. Evidence for Te 4+ ion conduction in α‐Te 2 MoO 7 is provided both directly by DC electrolysis results and theoretically by MEM analysis.