Low Emission Advanced Power Lab

Research Area III / Perovskite-typed Bifunctional Catalyst

Perovskite oxides are described by the general formula ABO3, where the A cation is conventionally larger than the B cation and the total cation charge of A and B is 6+, where A is a divalent (2+) or trivalent (3+) cation and B is a tetravalent (4+) or trivalent (3+) cation. The typical lattice structures are corner-sharing BO6 octahedral with small-sized cationic 6-fold coordination, in which the A site occupies the resulting cub-octahedral cavities in the 12-fold coordination arrangement. In the perovskite lattice, both the A and B sites can be partially substituted with cations of lower valence, which can easily form large amounts of extrinsic vacancies in the oxygen sub-lattice to maintain electro-neutrality and thereby promote the migration of oxygen ions through the lattice.

Bi-functional reaction for oxygen reduction and evolution are the essential electrochemical performance-limiting issues of the oxygen electrochemical devices including Li-O2 battery. Consequently, the perovskite-type haver previously emerged as efficient catalyst for these devices. However, they commonly exhibited good catalytic activity in the OER, whereas their ORR activity was lower than that of commercial precious metal catalyst.

Here within, we are exploring the various perovskite-typed oxide for Bi-functional catalyst and several promising materials were successfully synthesized through hydrothermal method and precious nano particles were decorated for the efficient OER/ORR activity in the secondary battery application. Furthermore, we have firstly investigated the distribution of relaxation times (DRT) method to understand these innovative performance and stability during the charge-discharge reaction through electrochemical impedance analysis (EIS) in the wide frequency range.

LEAP lab