The Zebra battery system for electric vehicle applications has been under development for more than ten years. This paper will review the status of the system development and will focus on the following aspects : A review of the basic electrochemistry of the sodium-nickel chloride electrochemical cell will be presented. In particular, the research and development work on the synthesis and manufacture of pure phase beta "-alumina materials will be discussed. In conclusion, the integration of the electrochemical cells into a traction battery for electric vehicle applications will be described.