Operando Monitoring of the Solution-Mediated Discharge and Charge Processes in a Na–O2 Battery Using Liquid-Electrochemical Transmission Electron Microscopy

NaO2 operando

Although sodium–oxygen (Na–O2) batteries show promise as high-energy storage systems, this technology is still the subject of intense fundamental research, owing to the complex reaction by which it operates. Research by the Peter Bruce Group and collaborators at CNRS in Amiens as reported in Nature Letters presents for the first time the use of a Na–O2 microbattery using a liquid aprotic electrolyte coupled with fast imaging transmission electron microscopy to visualize, in real time, the mechanism of NaO2 nucleation/growth. The formation of NaO2 cubes during reduction occurs by a solution-mediated nucleation process and subsequent oxidation of NaO2 also proceeds via a solution mechanism.