Main Challenges for High Performance NAS Battery: Materials and Interfaces

The progress in the research work and real applications of sodium-sulfur (NAS) battery in large scale energy storage is introduced. The key materials and interfaces of the battery, particularly the role of Shanghai Institute of Ceramics, Chinese Academy of Sciences (SICCAS), are systematically reviewed. As the most important and difficult part, the high-quality beta- alumina ceramic electrolyte tubes are prepared by a low-cost solid state reaction process; their sealing performance and interfacial behavior with molten sodium and sulfur electrodes could be substantially improved by glass ceramic type sealants and surface modification, respectively. Combination of carbon and additives like SiO2 with different wetting behaviors for sulfur and the discharge product sulfides is shown to be significant in improving the electrochemical performances of NAS battery. Conductive ceramic coatings are developed as anti-corrosion media of the current collector of sulfur electrode; this is identified as an effective route to protect the metal parts.