▎ 摘　　要

Despite the intrinsic advantages of ultra-high theoretical capacity and energy density of lithium-O-2 batteries, there remain several critical issues to be resolved, especially the two concerning poor cyclability and rate capability. In this work, CxNy particles@N-doped porous graphene (CxNy@NPG) with a novel three-dimensional architecture is successfully synthesized via a simple template method and employed as the cathode catalyst of Li-O-2 batteries. It is surprisingly found that the as-synthesized CxNy@NPG cathode not only demonstrates a remarkable cycling performance of 200 cycles at 1000 mA g(-1) but also an intriguing high-rate capability with 8892 mA h g(-1) at 1000 mA g(-1), both of which can be attributed to a synergistic effect between the unique 3D porous structure and an effective N-doping. Specifically, it is believed that the unique porous 3D structure will, on one hand, build numerous microchannels, thus facilitating rapid O-2 diffusion, and on the other hand, provide sufficient storage space to accommodate adequate discharge products. Indispensably, it is also believed that the N-doped porous graphene enables improved bifunctional catalytic activities towards both oxygen reduction reaction (ORR) and oxygen evolution reaction (OER), thus decreasing the discharge/charge overpotential, and reducing undesired side reactions. It is anticipated that the new 3D porous CxNy@NPG provides an inspiring route to design long cycling and high-rate performance cathodes for Li-O-2 batteries.