UMERC Special Seminar Electrochemical Energy Storage: from K-Air to Solar Battery
Prof. Yiying Wu Department of Chemistry and Biochemistry,
The Ohio State University, Columbus, Ohio 43210, USA
Alkali metal-oxygen batteries (Li-O2, Na-O2, and K-O2) are of great interests for energy storage because of their unparalleled theoretical energy densities I will present the invention of a K–O2 battery that uses K+ ions to capture superoxide (O2 - ), forming the thermodynamically stable KO2 product. This allows for the battery to operate through the facile one-electron redox process of O2/ O2 - . This invention has elegantly solved the kinetic challenge in oxygen reduction/evolution without using any catalysts. I will then present our recent progress in “solar battery”, which possesses the dual functions of solar energy harvesting and storage in a single device. An example is 'lithium−iodine solar flow battery' that brings together a lithium–iodine redox-flow battery and a dyesensitized photoelectrode. The photoexcited electron transfer between the photoelectrode and the iodine catholyte enables solar-assisted charging of the flow battery. Such a hybrid device has promising applications in building integrated solar harvesting/storage.