Feng Lixia, Li Yongliang, Sun Lingna, Mi Hongwei, Ren Xiangzhong, Zhang Peixin
College of Chemistry and Environmental Engineering, Shenzhen University, Shenzhen, Guangdong 518060, P.R. China.
Nanoscale. 2019 Aug 8;11(31):14769-14776. doi: 10.1039/c9nr03521d.
Lithium-oxygen batteries have received extensive attention due to their high theoretical energy density and environmental friendliness. Herein, CoO-Co3O4 nanoparticles coated on nitrogen-doped hollow carbon spheres (N-HC@CoO-Co3O4) are prepared by a simple method, and N-HC@CoO-Co3O4 when used as the cathode material for a lithium-oxygen battery shows high catalytic performance. The nitrogen-doped hollow carbon spheres not only ensure an ultra-high specific surface area for the accommodation of the Li2O2 discharge products but also provide more reactive sites. CoO-Co3O4 nanoparticles supported on the surface of the nitrogen-doped hollow carbon spheres can effectively catalyze the formation and decomposition of worm-like Li2O2. The batteries assembled with N-HC@CoO-Co3O4 catalysts exhibit reduced overpotential, improved cycling performance, and high rate capability. Ultra-high discharge capacities of 24 265 mA h g-1 at a current density of 300 mA g-1 and 3622 mA h g-1 at a current density of 1000 mA g-1 are obtained. With a cutoff capacity of 500 mA h g-1, the battery with an N-HC@CoO-Co3O4 electrode can reach more than 112 cycles. This research offers new insights into the design of heterostructured oxide catalysts for Li-O2 batteries.
锂氧电池因其高理论能量密度和环境友好性而受到广泛关注。在此，通过一种简单的方法制备了包覆在氮掺杂空心碳球（N-HC@CoO-Co3O4）上的CoO-Co3O4纳米颗粒，并且N-HC@CoO-Co3O4用作锂氧电池的阴极材料时表现出高催化性能。氮掺杂空心碳球不仅确保了超高的比表面积以容纳Li2O2放电产物，还提供了更多的活性位点。负载在氮掺杂空心碳球表面的CoO-Co3O4纳米颗粒可以有效地催化蠕虫状Li2O2的形成和分解。用N-HC@CoO-Co3O4催化剂组装的电池表现出降低的过电位、改善的循环性能和高倍率性能。在电流密度为300 mA g-1时获得了24265 mA h g-1的超高放电容量，在电流密度为1000 mA g-1时获得了3622 mA h g-1的超高放电容量。在截止容量为500 mA h g-1的情况下，具有N-HC@CoO-Co3O4电极的电池可以达到112次以上的循环。这项研究为锂氧电池异质结构氧化物催化剂的设计提供了新的见解。
