微波法合成Ni(OH)_2/RGO复合材料及其电化学性能研究

Microwave synthesis and electrochemical performance of nickel hydroxide/graphene composite

利用改进的Hummers法制备氧化石墨烯(GO),以GO为碳源、Ni(NO_3)_2为镍源、尿素为沉淀剂,采用微波二甲基亚砜溶剂法一步成功合成α-Ni(OH)_2/还原氧化石墨烯(α-Ni(OH)_2/RGO)复合电极材料,研究了不同微波功率、不同GO与Ni(OH)_2质量比对复合材料性能的影响。采用X射线衍射和扫描电镜测试其结构、表面微观形貌;利用恒电流充放电技术对其电化学性能进行研究。结果表明:α-Ni(OH)_2在石墨烯片层上形核长大,当微波功率为600W,GO∶Ni(OH)_2=1∶6(质量比)时,0.2C放电比容量可以达到326.7mAh/g,从0.2C到5C,放电比容量仅下降了15.6%,显示了高的容量保持率和循环稳定性。

The preparation method of nickel hydroxide/graphene composites, which was synthesized sucessfully using nickel nitrate and graphite oxide as raw material,using urea as the precipitator and dimethyl sulfoxide as solvent by microwave method was reported. And, graphite oxide was prepared by improved hummers method with graphite powder. The influence of different mass ratio of GO to nickel hydroxide and microwave heating power on properties of composite materials were researched. The morphologies and structures of the prepared materials were characterized by X-ray diffrac- tion（XRD） and scan electron microscopy（SEM）. The electrochemical characteristics were analyzed by means of galvanosta- tic charge-discharge cycling technology. The results showed that alpha Ni（OH）2 grown as nucleation onto graphene layers. the highest discharge capacity was 326.7mAh/g at 0.2C rate while microwave heating power was 600W,the discharge ca- pacity of composites with a quality ratio of 1：6 fell by 15.6 percent from 0.2 to 5C rate and demonstrated high capacity re- tention ratio and cycle stability.