Affiliation:
1. Department of Chemistry and Biochemistry Florida State University Tallahassee FL 32306 USA
2. Materials Science and Engineering Florida State University Tallahassee FL 32310 USA
3. Center of Interdisciplinary Magnetic Resonance National High Magnetic Field Laboratory Tallahassee FL 32310 USA
Abstract
AbstractAll‐solid‐state potassium batteries emerge as promising alternatives to lithium batteries, leveraging their high natural abundance and cost‐effectiveness. Developing potassium solid electrolytes (SEs) with high room‐temperature ionic conductivity is critical for realizing efficient potassium batteries. In this study, we present the synthesis of K2.98Sb0.91S3.53Cl0.47, showcasing a room‐temperature ionic conductivity of 0.32 mS/cm and a low activation energy of 0.26 eV. This represents an increase of over two orders of magnitude compared to the parent compound K3SbS4, marking the highest reported ionic conductivity for non‐oxide potassium SEs. Solid‐state 39K magic‐angle‐spinning nuclear magnetic resonance on K2.98Sb0.91S3.53Cl0.47 reveals an increased population of mobile K+ ions with fast dynamics. Ab initio molecular dynamics (AIMD) simulations further confirm a delocalized K+ density and significantly enhanced K+ diffusion. This work demonstrates diversification of the anion sublattice as an effective approach to enhance ion transport and highlights K2.98Sb0.91S3.53Cl0.47 as a promising SE for all‐solid‐state potassium batteries.
Funder
Division of Materials Research