The reporter learned from the University of Science and Technology of China that the team of the Academician Qian Yitai and the group of Professor Wang Gongming studied the kinetic behavior of metallic cobalt-based compounds in lithium-sulfur chemistry by combining experiments and theory. The position of the p-energy band of the anion's valence electron relative to the Fermi level is the main factor affecting the kinetics of the electron transfer reaction of the lithium-sulfur battery interface. The research results have been published in the magazine "Joule", the world's top energy materials journal.
Lithium-sulfur (Li-S) batteries have attracted much attention due to their high theoretical specific capacity, energy density and low cost. However, the dissolution of lithium polysulfide, an intermediate product during charge and discharge, causes a shuttle effect, which severely limits its practical application.
Researchers have studied the properties of the conversion kinetics and found that the prepared metal cobalt-based compounds exhibit completely different electrochemical kinetic behaviors.
The DFT simulation results and the simultaneous charge differential density analysis show that the p-band center of the anion valence electron is found by attempting to correlate the p-band center position of the anion valence band of different cobalt-based compounds with the kinetics of electrochemical conversion of polysulfide compounds. Relative to the position of Fermi level, it can effectively regulate the kinetics of interface electron transfer reaction, which becomes the main factor affecting the chemical kinetics of Li-S. This result will guide the application of Li-S battery.
