Facile and Cost Effective Synthesized Mesoporous Spinel NiCo2O4 as Catalyst for Non-Aqueous Lithium-Oxygen Batteries

Abstract

The electrochemical performance of lithium-oxygen batteries can be significantly improved by employing a suitable catalyst to enhance the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER). Herein, a versatile, effective and economic co-precipitation synthesis of spinel NiCo2O4 with an urchin-like structure has been reported as an electrocatalyst for rechargeable non-aqueous Li-O2 batteries. The spherical urchin-like structure of spinel NiCo2O4 was formed without the use of any template or surfactant. The oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) kinetics in the Li-O2 batteries could be drastically improved by employing the effective NiCo2O4 catalyst, achieving a higher discharge potential and rate. In particular, the urchin-like structure of the catalyst not only provides more electrocatalytic sites but also promotes mass transport in the electrolyte. In addition, mesoporous NiCo2O4 can efficiently catalyze the formation and decomposition of Li2O2. The Li-O2 battery containing the urchin-like NiCo2O4 catalyst exhibited the highest specific capacity of about 7309 mA h g−1 at 0.2 mA cm−2. The integrity and porosity of spinel NiCo2O4 had a significant effect on the performance of the Li-O2 battery with reasonable specific capacity and cyclability, suggesting that the NiCo2O4-based materials can be effective catalysts for oxygen electrode in high performance Li-O2 batteries.