(i) Alkaline-metal ion batteries
The alkaline-metal ion batteries operate with very similar reaction mechanism, namely, insertion/extraction of alkaline ions into/from a cathode and the corresponding extraction/insertion of alkaline-metal ions from and into an anode. The life span of the batteries mainly depends on the reversibility of electrodes during cycles. Searching for stable electrodes and understanding the kinetics of alkaline-metal ions and charge compensation in electrodes are crucial for battery performance improvement.
(ii) Metal-air batteries
Our research is mainly related to Li-, Na- or K-air batteries. The reaction mechanism is dependent on the various discharge products due to their thermodynamic stability. Big challenges faced by such metal-air batteries are the low decomposition efficiency of discharge products, stability of electrolytes and electrodes against oxygen radicals generated in a charging process, and shuttling effect of the dissolved discharge products. How to alleviate or solve these problems and hence improve the battery performance is the focus of our research.