School of Materials Science & Engineering, Beijing Institute of Technology , Beijing 100081, China.
Department of Chemistry and Biochemistry, The Ohio State University , 100 West 18th Avenue, Columbus, Ohio 43210, United States.
ACS Appl Mater Interfaces. 2017 Feb 8;9(5):4382-4390. doi: 10.1021/acsami.6b14071. Epub 2016 Nov 30.
Large energy-storage systems and electric vehicles require energy devices with high power and high energy density. Lithium oxygen (Li-O) batteries could achieve high energy density, but they are still facing problems such as low practical capacity and poor cyclability. Here, we prepare activated carbons (MGACs) based on the natural plant Miscanthus × giganteus (MG) through slow pyrolysis. It possesses a large surface area, plenty of active sites, and high porosity, which are beneficial to the utilization of oxygen electrode in Li-O batteries. The MGACs-based oxygen electrode delivers a high specific capacity of 9400 mAh/g at 0.02 mA/cm, and long cycle life of 601 cycles (with a cutoff capacity of 500 mAh/g) and 295 cycles (with a cutoff capacity of 1000 mAh/g) at 0.2 mA/cm, respectively. Additionally, the material exhibits high rate capability and high reversibility, which is a promising candidate for the application in Li-O batteries.
大型储能系统和电动汽车需要具有高功率和高能量密度的能源设备。锂氧（Li-O）电池可以实现高能量密度，但它们仍面临实际容量低和循环性能差等问题。在这里，我们通过缓慢热解天然植物芒草（Miscanthus × giganteus，MG）制备了基于活性炭（MGACs）。它具有大的表面积、丰富的活性位和高的孔隙率，有利于锂氧电池中氧电极的利用。基于 MGACs 的氧电极在 0.02 mA/cm 时具有 9400 mAh/g 的高比容量，在 0.2 mA/cm 时分别具有 601 次循环（截止容量为 500 mAh/g）和 295 次循环（截止容量为 1000 mAh/g）的长循环寿命。此外，该材料表现出高倍率性能和高可逆性，是应用于 Li-O 电池的有前途的候选材料。
