As global society moves toward a more sustainable future with the implementation of renewable energy sources to transition away from traditional fossil fuels, research efforts have been focused on the development of various types of electrochemical energy storage. The development of sodium systems with higher energy density, safety and cyclability has been an ongoing pursuit. Solid-state batteries that utilize a stable solid-state electrolyte (SSE) could potentially address these issues as it enables the use of highly energy density metal-anodes and suppresses side reactions that may lead to safety issues.
This study aims explores sodium-based zirconate SSE for sodium-ion batteries to gain a better understanding of the underlying conduction mechanisms in these systems. Zirconium-based SSE generally exhibits good thermal and chemical stability owing to Zr’s highly stable oxidation state and its strong bonding with oxygen. This high thermodynamic stability enables higher stability at electrode and electrolyte interface and enhances the cyclability, while the rigid structure from strong bonding can provide resistance to mechanical stress.
Na2ZrO3 is synthesized and characterised using X-ray diffraction, neutron powder diffraction, and X-ray absorption spectroscopy. There are limited studies on this material as a battery material, with no reporting on its application as a solid-state electrolyte in a working cell. Its simplicity in both elemental composition and synthesis also make it ideal for potential large-scale deployment. This work will highlight the stability and performance of Na2ZrO3 using symmetric cells and solid-state cells. The impact of chemical substitution will be also explored.