LaMnO3-diamond composites as efficient oxygen reduction reaction catalyst for Zn-air battery

Abstract The development oxygen reduction reaction (ORR) catalysts with strong chemical durability are crucial for various renewable energy applications, such as metal–air batteries. In this work, a series of LaMnO 3 -diamond composites with varied LaMnO 3 mass contents supported on micron diamond was synthesized using a sol-gel method. The as-prepared composites were characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, Raman spectroscopy, and Fourier transform infrared spectroscopy. Results showed that the peak position of LaMnO 3 shifted to a low angle after the introduction of diamond, and perovskite particles were uniformly distributed on the surface of diamond, forming a network structure. The electrocatalytic activities of the composites were investigated by rotating disk electrode method, galvanostatic discharge analysis, and AC impedance spectroscopy. The LaMnO 3 -diamond composites showed better ORR performance than LaMnO 3 , and 33%LaMnO 3 -diamond exhibited excellent electrocatalytic activity. This research widens the application range of micron-sized diamond and provides a new carrier for perovskite in metal–air batteries.