Lithiation-Induced Non-Noble Metal Nanoparticles for Li-O2 Batteries.

ABSTRACT

Low-cost and highly active electrocatalysts are attractive for Li-O2 applications. Herein, a 3D interconnected plate architecture consisting of ultrasmall Co-Ni grains embedded in lithium hydroxide nanoplates (Co2Ni@LiOH) is designed and prepared by a lithiation strategy at room temperature. This catalyst exhibits a remarkably reduced charge potential of ∼3.4 V at 50 µA cm-2, which leads to the high roundtrip efficiency of ∼79%, among the best levels reported and a cycle life of up to 40 cycles. The well-aligned network facilitates the oxygen diffusion and the electrolyte penetration into the electrode. The enhanced electrical conductivity network improves the charge transport kinetics and more active sites are exposed, which facilitate the adsorption and dissociation of oxygen during the oxygen reduction reaction and the oxygen evolution reaction. This new catalyst design inspires the development of an effective non-noble metal catalyst for Li-O2 batteries.