Synergized multimetal oxides with amorphous/crystalline heterostructure as efficient electrocatalysts for lithium-oxygen batteries

Abstract

High theoretical specific energy of rechargeable lithium-oxygen (Li-O-2) batteries makes them very promising in the development of long driving range electric vehicles and energy storage on large-scale. However, the large polarization and poor cycling stability associated with insufficient catalytic cathodes and the insulating nature of discharge products limit their practical applications. Here, the fabrication of a trimetallic CoFeCe oxide with an amorphous/crystalline heterostructure acting as an electrocatalyst for the Li-O-2 battery cathode is reported. The best-performing CoFeCe oxide cathode manages to deliver an initial discharge capacity of 12 340 mAh g(-1), while maintaining an impressively enhanced cyclic stability over 2900 h at 100 mA g(-1). As revealed by combined experimental results and density functional theory (DFT) analysis, synergistic interaction between oxide components, amorphous-crystalline domains, unique heterostructure with minimized lattice mismatch, and the enhanced adsorption of the key intermediate LiO2 are critical factors in boosting the electrocatalytic activity of CoFeCe toward the formation of decomposable Li2O2. This work offers a new insight to rationally design and synthesize an effective multimetal oxide electrocatalyst for the Li-O-2 battery cathode.