Improved Electrocatalytic Activity of Three-Dimensional Open-Structured Co3O4@MnO2 Bifunctional Catalysts of Li-O2 Batteries by Inducing the Oriented Growth of Li2O2

Rational structure and morphology design of catalytic cathode materials is the key to realize excellent performances of lithium-oxygen batteries (LOBs). Herein, a three-dimensional (3D) open-structured Co₃O₄@MnO₂ heteromatrix has been designed through a facile two-step hydrothermal method. Unexpectedly, when it serves as oxygen reduction reaction/oxygen evolution reaction bifunctional catalytic cathodes for lithium-oxygen cells, the 3D open-structured Co₃O₄@MnO₂ heteromatrix-catalyzed LOBs exhibit outstanding electrochemical performances (a high specific capacity of 12,980 mA h g–¹ during the initial discharge and long cycle life of 331, 197, and 14 times with specific capacities fixed at 500, 1000, and even 3000 mA h g–¹, respectively), obviously superior to reported batteries based on low-dimensional and closed-ended catalysts. We find that the enhanced electrochemical performances are ascribed to the bifunctional catalyst and the 3D open structure of the Co₃O₄@MnO₂ heteromatrix, which can guide the homogeneous and fluffy deposition of discharge products Li₂O₂, demonstrating a promising application in both LOBs and flexible/wearable Li-air batteries.