The team of Academician Qian Yitai and Professor Wang Gongming of the University of Science and Technology of China studied the kinetic behavior of metal cobalt-based compounds in lithium-sulfur chemistry by combining experiments and theory, and found that p-energy of valence electrons of anions in cobalt-based compounds The position with the center relative Fermi level is the main factor affecting the dynamics 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 charging and discharging, 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 achievement will guide the development of Li-S battery applications.