一步溶剂热法合成CoO/Ti_3C_2复合材料及其电化学性能研究

One-step solvothermal synthesis of CoO/Ti_3C_2 composite with enhanced electrochemical performance

采用溶剂热法一步合成CoO/Ti_3C_2复合材料,通过X射线衍射(XRD)、扫描电镜(SEM)对材料的结构及形貌进行了表征.在复合材料中,二维层状Ti_3C_2作为导电基体的同时有效缓冲了CoO在充放电过程中的体积变化和团聚.CoO纳米微球均匀的负载在Ti_3C_2层间,作为一个间隔器有效防止了Ti_3C_2层的堆叠,提高材料的比表面积的同时提供了锂离子扩散的通道.与单独的CoO和Ti_3C_2相比,CoO/Ti_3C_2复合材料作为锂离子电池电极具有较高的电化学性能,包括良好的循环性能和倍率性能.CoO/Ti_3C_2复合材料循环十次以后,电极材料的库仑效率基本维持在99%左右,充放电循环300次后仍能够获得415mAh g-1的可逆比容量.

CoO/Ti 3C 2 composite was synthesized by a facile one-step solvothermal method.The phase and microstructure of CoO/Ti 3C 2 composite were analyzed by XRD and SEM.In the as-prepared composites,the two-dimensional materials Ti 3C 2 can not only provide a conductive matrix,but also buffer the volume changes of CoO and restrain the aggregation of CoO particles during charge-discharge cycling.The CoO nanospheres are uniformly anchored into the 2D Ti 3C 2,acting as spacers to effectively avoid the close restacking of Ti 3C 2,increase the surface area and provide an additional channel for the diffusion of lithium ions.Compared to the bare CoO and Ti 3C 2,the CoO/Ti 3C 2 composite as Li-ion battery anodes show dramatically improved electrochemical performance,including cycling stability and rate capability.Remarkably,CoO/Ti 3C 2 nanocomposite show outstanding cycling stability that the coulombic efficiency is around 99%after 10 cycles and the capacity can remain about 415 mAh g-1 after 300 cycles.