Department of Materials Science and Engineering, Korea University , Anam-Dong, Seongbuk-Gu, Seoul 136-713, South Korea.
ACS Appl Mater Interfaces. 2016 Mar;8(10):6449-56. doi: 10.1021/acsami.5b11963. Epub 2016 Mar 4.
The electrochemical properties of hollow cobalt oxide and cobalt selenide microspheres are studied for the first time as anode materials for Na-ion batteries. Hollow cobalt oxide microspheres prepared by one-pot spray pyrolysis are transformed into hollow cobalt selenide microspheres by a simple selenization process using hydrogen selenide gas. Ultrafine nanocrystals of Co3O4 microspheres are preserved in the cobalt selenide microspheres selenized at 300 °C. The initial discharge capacities for the Co3O4 and cobalt selenide microspheres selenized at 300 and 400 °C are 727, 595, and 586 mA h g(-1), respectively, at a current density of 500 mA g(-1). The discharge capacities after 40 cycles for the same samples are 348, 467, and 251 mA h g(-1), respectively, and their capacity retentions measured from the second cycle onward are 66, 91, and 50%, respectively. The hollow cobalt selenide microspheres have better rate performances than the hollow cobalt oxide microspheres.
首次研究了作为钠离子电池阳极材料的中空氧化钴和硒化钴微球的电化学性能。通过一锅喷雾热解法制备的中空氧化钴微球，通过使用硒化氢气体的简单硒化过程转化为中空硒化钴微球。在 300°C 下硒化的钴硒化物微球中保留了 Co3O4 微球的超细纳米晶。在电流密度为 500 mA g(-1)时，Co3O4 和在 300 和 400°C 下硒化的钴硒化物微球的初始放电容量分别为 727、595 和 586 mA h g(-1)。相同样品在 40 次循环后的放电容量分别为 348、467 和 251 mA h g(-1)，从第二次循环开始的容量保持率分别为 66、91 和 50%。中空钴硒化物微球的倍率性能优于中空氧化钴微球。
