中空CoMn_2O_4/石墨烯气凝胶复合物的制备及其电化学性能

Preparation and Electrochemical Performance of Hollow CoMn_2O_4/Graphene Aerogel Hybrids

以碳球为模板通过溶剂热-煅烧的方法合成中空CoMn_2O_4,并对其表面进行阳离子改性。以改性CoMn_2O_4和氧化石墨烯(GO)为原料,使用水热法及冷冻干燥技术制备出中空CoMn_2O_4/石墨烯气凝胶(GA)复合物。采用TEM、SEM、XRD、BET对样品的形貌和结晶结构进行表征;采用CHI660E电化学工作站对样品进行电化学性能评估。结果表明,中空CoMn_2O_4纳米球紧紧地固定在三维多孔网络结构GA中,GA的掺入不仅有效缓解了充放电过程中CoMn_2O_4负极的体积膨胀效应,也加快了锂离子电子传输速率,进而大大提高了电池的循环性能和倍率性能。

The hollow CoMn2O4 was synthesized by a solvothermal-anneal method using carbon spheres as template, and the surface was further modified by cation. The hollow CoMn2O4/GA hybrids were prepared by a hydrothermal method and freeze-drying technique using the hollow CoMn2O4 and GO as raw materials. TEM, SEM, XRD, and BET were used to characterize the morphology and crystallographic structures of the samples. The electrochemical workstation was used to evaluate the electrochemical properties of the samples. The results revealed that the hollow CoMn2O4 was tightly anchored on the 3D porous network structure of GA. The introduce of GA was not only to effectively relieve volume expansion of CoMn2O4 anode during the discharge-charge process, but also facilitated lithium ion and electron transport rate. Thus, the cycling performance and ratecapability of battery were greatly improved.