石墨烯/钴镍双金属氢氧化物复合材料的制备及电化学性能研究

采用微波辐射与高温裂解相结合的二步还原法制备石墨烯。二步还原使氧化石墨被充分还原和剥离,所得到的石墨烯有较好的传导性,其比表面达675.4 m2.g-1。以此石墨烯为原料,水热法合成出石墨烯/钴镍双金属氢氧化物复合材料,并考察了复合材料作为超级电容电极材料的电化学性能。研究发现,褶皱的石墨烯纳米片均匀分散在钴镍双金属氢氧化物中,这改善了钴镍双金属氢氧化物的传导性和结构稳定性。在0.25 A.g-1电流密度下,复合材料的比电容量是800.2 F.g-1。当电流密度增加至10 A.g-1,比电容量为386.5 F.g-1,恒电流充-放电500次后比电容量仍能保持99%以上,这些呈示该复合材料具有优良的电化学性能。

Synthesis and Electrochemical Property of Graphene/Co-Ni Double Hydroxides Composites

Two step reduction method that microwave irradiation combined with high temperature pyrolysis was employed for the preparation of graphene. The two step reduction results in fully reduction and exfoliation of graphite oxide. The obtained graphene is of good conductivity and its specific surface area is up to 675.4 m²·g^-1. In this work, the as-prepared graphene was used as raw materials for the fabrication of graphene/Co-Ni double hydroxides composites with the hydrothermal synthesis method. Electrochemical property of the composites was also investigated as supercapacitor electrode materials. The research revealed the wrinkled graphene nanosheets were well dispersed in the Co-Ni double hydroxides. This improved conductivity and structure stability of the Co-Ni double hydroxides. At 0.25 A·g^-1 discharge current, the supercapacitor specific capacitance was 800.2 F·g^-1. With increase of current density up to 10 A·g^-1, the discharge current specific capacitance was 386.5 F·g^-1. After galvanostatic charge-discharge 500 times, the specific capacitance also remains more than 99%, indicating that the composites is of excellent electrochemical performance.