In situ Regulating the phase structure of Ce-based catalytic sites to boost the performance of zinc-air batteries

Abstract

We report an iodide-induced phase regulation strategy to in-situ synthesize a cerium-based catalyst (Ce-N4O2 SACs) with high Ce loading (15.9 wt%), radicals scavenging ability and high-density Ce-N4O2 sites on the surface of porous nanocarbon frameworks. The oxygen reduction reaction (ORR) mechanisms on the Ce-N4O2 SACs are recorded by in-situ Raman spectra. Moreover, the density functional theory (DFT) calculations show that the Ce-N4O2 structure can optimize the electronic configuration of Ce and positively promote the activation of adsorbates. As expected, this catalyst delivers excellent ORR electrocatalytic activity and stability (half-wave potential decay ∼11 mV after cycling for 30k cycles). The assembled primary zinc-air battery demonstrates a remarkable energy density (ED) of 946 Wh kgZn−1 and exhibits predominant long-term durability (ED reduction ∼3.5 % after for 130 h). This work shows that rare-earth single-atom catalysts, subjected to regulation encompassing structure-density-configuration-mass transfer, hold great promise in realizing high ED metal-air batteries.