Solid electrolytes (SEs) have attracted considerable attention in applications such as energy storage systems and electrical devices due to their intrinsic safety and high energy density. Among them, layered oxide‐based SEs exhibit high stability, reasonable ionic conductivity, and lower sintering temperatures compared with other oxide‐based SEs. Nevertheless, the demand for higher ionic conductivity and lower synthesis temperatures still persists. To address these challenges, this work explores a substitution strategy for Na 2 Zn 2 TeO 6 (NZTO), which shows the highest ionic conductivity among layered oxide SEs. Iron (Fe 3+ ), one of the most earth‐abundant elements, is employed to partially substitute Zn 2+ in NZTO to enhance both stability and performance. This approach successfully improves ionic conductivity and lowers sintering temperature. Specifically, the ionic conductivity increases significantly from 0.469 mS/cm in pristine NZTO to 0.850 mS/cm at 25°C with 0.1 Fe substitution, and a pure P2 NZTO phase is obtained at 750°C, compared with 900°C for pristine NZTO. Furthermore, a 12.9% capacity enhancement and improved stability are achieved when fabricating a solid‐state cell with 0.1 Fe 3+ ‐substituted NZTO compared with pristine NZTO, confirming its potential for applicability in all‐solid‐state batteries.
Lee et al. (Sat,) studied this question.