液相还原法和热还原法制备石墨烯的电容性能

Capacitive performance of graphene prepared by liquid-phase reduction and thermal reduction methods

用改进的Hummers法制备前驱体,通过液相还原和热还原两种不同的方法制备石墨烯电极材料。对两种工艺制备的石墨烯材料进行物理性能测试。选择热还原法制备的形貌与分散结果较好的石墨烯作为超级电容器电极材料,组装扣式超级电容器。通过恒流充放电测试、循环伏安测试和交流阻抗测试等电化学分析手段,考察石墨烯电极材料的电容特性、容量特性和循环特性。石墨烯电极材料具有理想的双电层电容特性和循环稳定性,以200 mA/g在-0.2~0.8 V循环500次,容量保持率为95.9%。为了充分发挥石墨烯的高容量优势,后续将通过改性或复合处理继续进行研究。

Graphene electrode materials are prepared by two different methods,liquid phase reduction and thermal reduction,the precursor is prepared by improved Hummers method.The physical properties of graphene materials prepared by two processes are tested.The graphene prepared by thermal reduction method with good morphology and dispersion results is selected as the electrode material of supercapacitor,the button supercapacitor is assembled.The capacitance,capacity and cycle characteristics of graphene electrode materials are investigated through galvanostatic charge-discharge tests.The graphene electrode materials have ideal double-layer capacitance characteristics and cycling stability.After 500 cycles at 200 mA/g in-0.2-0.8 V,the capacity retention rate is 95.9%.In order to give full play to the high capacity advantage of graphene,further research will be carried out through modification or composite treatment.