Synthesis and Interface Stabilization of Chalcogenide-Based Solid Electrolytes in Solid-State Sodium Batteries

Abstract

Rechargeable sodium (Na) batteries that utilizing solid-state ion conductors have attracted intense attentions for large-scale energy storage systems due to the abundant resources of Na compounds and electrochemical voltage (2.70 V vs. 3.05V for Li). So far, the most popular inorganic Na-ion SEs include oxides, halides, and chalcogenides such as Na3PhCh4 (Ph=P, Sb; Ch=S, Se) etc. In specific, Na3SbCh4 (Ch=S, Se) chalcogenide conductors exhibit impressive ionic conductivity at room temperature due to vacancy-assisted three-dimensional (3D) ion transport channels. In this talk, we will introduce our works on the studies on in-situ synthesis of Na chalcogenide solid electrolytes (SEs) and several strategies for interface stabilization of such SEs towards Na anode. The in-situ synthesis studies of Na3SbCh4 (Ch=S, Se) reveal the structural evolutions during the solid-state reaction process.1 Besides, efficient interface stabilization strategies have been demonstrated to enable solid-state Na metal batteries that using Na as the anode, and metal sulfide (TiS2 or FeS2) as the cathode.2, 3 For instance, phase transition interlayer (PEG-PPG-PEG) has been successfully proved to prevent the side reactions between the Na3SbS4 SE and Na metal and contribute to the uniform Na deposition at interface to prevent dendrite formation and growth. The goal of our work is to develop novel chalcogenide Na conductors and promote their applications in solid-state Na batteries. Halacoglu, S.; Chertmanova, S.; Chen, Y.; Li, Y.; Rajapakse, M.; Sumanasekera, G.; Narayanan, B.; Wang, H., Visualization of Solid-State Synthesis for Chalcogenide Na Superionic Conductors by in-situ Neutron Diffraction. ChemSusChem 2021, 14 (23), 5161-5166.Li, Y.; Arnold, W.; Halacoglu, S.; Jasinski, J. B.; Druffel, T.; Wang, H., Phase-Transition Interlayer Enables High-Performance Solid-State Sodium Batteries with Sulfide Solid Electrolyte. Advanced Functional Materials 2021, 31 (28), 2101636.Li, Y.; Halacoglu, S.; Shreyas, V.; Arnold, W.; Guo, X.; Dou, Q.; Jasinski, J. B.; Narayanan, B.; Wang, H., Highly efficient interface stabilization for ambient-temperature quasi-solid-state sodium metal batteries. Chemical Engineering Journal 2022, 434, 134679.