Nanoscale alloying effect of gold–platinum nanoparticles as cathode catalysts on the performance of a rechargeable lithium–oxygen battery

Abstract

The understanding of nanoscale alloying or the phase segregation effect of alloy nanoparticles on the catalytic properties is important for a rational design of the desired catalysts for a specific reaction. This paper describes findings of an investigation into this type of structural effect for carbon-supported bimetallic gold–platinum nanoparticles as cathode catalysts in a rechargeable lithium–oxygen battery. The nanoscale structural characteristics in terms of size, alloying and phase segregation were shown to affect the catalytic properties of the catalysts in the Li–O2 battery. In addition to the composition effect, the catalysts with a fully alloyed phase structure were found to exhibit a smaller discharge–charge voltage difference and a higher discharge capacity than those with a partial phase segregation structure. This finding is significant for the design of alloy nanoparticles as air cathode catalysts in rechargeable lithium–air batteries, demonstrating the importance of the control of the nanoscale composition and phase properties.