Gradient Mn-La-Pt Catalysts with Three-layered Structure for Li-O₂ battery

Gradient Mn-La-Pt catalysts with three-layered structure of manganese dioxide (MnO₂), lanthanum oxide (La₂O₃), and Platinum (Pt) for Li-O₂ battery are prepared in this study. The mass ratio of the catalysts is respectively 5:2:3, 4:2:4, and 3:2:5 (MnO₂: La₂O₃: Pt) which is start from the side of the electrolyte. The relationship between morphology structure and electrochemical performance of gradient catalyst is investigated by energy dispersive spectrometry and constant current charge/discharge test. The Li-O₂ battery based on gradient Mn-La-Pt catalysts shows high discharge specific capacity (2707 mAh g^-1), specific energy density (8400 Wh kg^-1) and long cycle life (56 cycles). The improvement of the Li-O₂ battery discharge capacity is attributed to the gradient distribution of MnO₂ and Pt and the involvement of La₂O₃ that can improve the energy density of the battery. More important, this work will also provide new ideas and methods for the research of other metal-air battery.