Experimental and theoretical characteristic of single atom Co-N-C catalyst for Li-O2 batteries

Abstract

Single atom Co-N-C can be used as a low-cost cathode catalyst for Li-O2 batteries (LOBs) with abundant highly active sites and high efficient atom utilizations. In the present work, hierarchical porous single atom Co-N-C catalyst was prepared through acid etching from a Co/Co-N-C intermediate, featuring an efficient slack of volume expansion, easy mass transmission via the interconnected carbon-framework, and sufficient surface area to accommodate discharge products. The single atom Co-N-C catalyst exhibited a superior catalytic capacity for LOBs with a large specific capacity of 14075 mAh g-1 and a long cycle life of 340 cycles. The oxygen reduction reaction (ORR) / oxygen evolution reaction (OER) mechanisms of the discharge products of single atom Co-N-C catalyst were identified by using density functional theory (DFT) calculations, showing avenues for improving the future design of single atom catalyst.