Principal Investigator Yang Shao-Horn
Research efforts toward better understanding of the nonaqueous ORR mechanism and the design principles of highly active catalysts are critical to improve the discharge performance, which directly affects the deliverable gravimetric energy and power of Li-air batteries. We have identified an activity descriptor that governs the nonaqueous ORR activity of metal-based catalysts. We revealed that the nonaqueous Li+-ORR activity of metal surfaces primarily correlates to oxygen adsorption energy, forming a “volcano-type” trend. This volcano dependence suggests that the strength of oxygen binding on the catalyst surface greatly influences the Li+-ORR activity and can serve as a design guide for ORR catalyst for Li-air battery application. In addition, the activity trend found on the polycrystalline bulk surfaces was successfully translated into the discharge voltage of practical Li-O2 cells catalyzed by nanoparticle catalysts.