The sluggish redox reaction kinetics for aprotic Li-O2 batteries (LOBs) caused by the insulating discharge product of Li2O2 could result in the poor round-trip efficiency, low rate capability, and cyclic stability. To address these challenges, we herein fabricated NiCo2S4 supported on reduced graphene oxide (NiCo2S4@rGO), the surface of which is further modified via a unique low-pressure capacitive-coupled nitrogen plasma (CCPN-NiCo2S4@rGO). The high ionization environment of the plasma could etch the surface of NiCo2S4@rGO, introducing effective nitrogen doping. The as-prepared CCPN-NiCo2S4@rGO has been employed as an efficient catalyst for advanced LOBs. The electrochemical analysis, combined with theoretical calculations, reveals that the N-doping can effectively improve the thermodynamics and kinetics for LiO2 adsorption, giving rise to a well-knit Li2O2 formation on CCPN-NiCo2S4@rGO. The LOBs based on the CCPN-NiCo2S4@rGO oxygen electrode deliver a low overpotential of 0.75 V, a high discharge capacity of 10,490 mA h g-1, and an improved cyclic stability (more than 110 cycles). This contribution may pave a promising avenue for facile surface engineering of the electrocatalyst in LOBs and other energy storage systems.

Centre of Polymer and Carbon Materials Polish Academy of Sciences M Curie Sklodowskiej 34 Zabrze 41 819 Poland

College of Energy Soochow Institute for Energy and Materials InnovationS Soochow University Suzhou 215006 China

Institute of Environmental Technology VSB Technical University of Ostrava 17 Listopadu 15 Ostrava 70833 Czech Republic

Leibniz Institute for Solid State and Materials Research Dresden P O Box 270116 D 01171 Dresden Germany

Citace poskytuje Crossref.org