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

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 CeN4O2 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 kg(Zn)(-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.