NanoColloquium: Seung-Tae Hong - Exploration of Cathode Materials for Mg & Ca Ion Batteries
Monday, June 5, 2023
Pepco Room, Kim Engineering Building
301 405 0028
Professor, Energy Science & Engineering
Daegu Gyeongbuk Institute of Science and Technology
Exploration of Cathode Materials for Magnesium and Calcium Ion Batteries
Li-ion batteries (LIBs) are one of the most successful energy storage devices for portable electronics applications, electric vehicles, and utility grids. However, there are still strong needs for higher energy density and lower-price materials than what the LIB systems can provide. Environmental friendliness, reliability, safety, and plentiful sources could be typical advantages of magnesium and calcium materials over lithium. Rechargeable batteries utilizing reversible insertion of divalent ions such as Mg2+ and Ca2+ could be one of the strategies to overcome the capacity limit of LIBs and/or to produce lower price batteries. The divalency of such ions as the carrier ion can increase the capacity of a host material because each carrier ion can transfer two electrons to host materials.
Mg rechargeable batteries have received attention since the reversible Mg insertion into the Chevrel phase, Mo6S8, was demonstrated in 2000. Despite the enormous efforts over the last two decades, only a limited number of cathode materials have been reported as successful host materials. On the other hand, recent discoveries of reversible plating or alloying of calcium provoked considerable interest in calcium-based rechargeable batteries, particularly in the search for high-energy Ca cathode materials. Theoretical calculations also anticipate the development of positive materials. Nonetheless, only a few cathode materials have been reported so far, only to exhibit low energy-storage capability and poor cyclability.
In this talk, I will present the synthesis, structural and electrochemical properties of new cathode materials for nonaqueous magnesium and calcium-ion batteries, which were recently developed in our group. These stimulating discoveries will lead to the development of new strategies for obtaining high-energy-density batteries beyond LIBs.