在超级电容器领域,负极主要集中在碳基材料中,如活性炭,碳纳米管,石墨烯,石墨烯等等。然而,基于金属有机骨架(MOFs)作为负活性成分的材料相对罕见。在这里,通过水热法制备了一系列基于氧化石墨烯(GO)和钒酸盐基Fe-有机骨架的复合材料,即GO/Fe-VO4-BIPY。多金属氧酸盐基金属有机骨架(POMOF)在石墨烯表面上的沉积量通过改变POMOF的含量来调节。通过沉积,它可以有效减少石墨烯之间的积累,并增加POMOF的分散性。因此,所得材料的电荷存储性能大大提高。在这些材料中,GO/Fe-VO4-BIPY-1由于其在法拉第化学反应和双电层电容之间的优异协同作用而具有最突出的性能。与原始Fe-VO4-BIPY相比,GO/Fe-VO4-BIPY-1提供更优异的表面积,因此具有丰富的氧化还原反应位点,达到更好的电化学性能最好。与Ni(OH)2正极组装后,在850Wkg-1的功率密度下,最大能量密度为46.84Whkg-1。
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In the supercapacitor field, negative electrodes are mainly concentrated in carbon-based materials, such as activated carbon, carbon nanotubes, graphene, and so forth. However, materials based on metal-organic frameworks (MOFs) as negative active components are relatively rare. Herein, a series of composite materials based on graphene oxide (GO) and
vanadate-based Fe-organic frameworks have been prepared by hydrothermal method namely GO/Fe-VO4-BIPY. The deposition amount of polyoxometalate-based metal-organic frameworks (POMOFs) on the surface of graphene is adjusted by changing the content of POMOFs. Through the deposition, it can effectively reduce the accumulation between graphene, and increase the dispersion of POMOFs. As a result, the charge storage performance of the as-obtained materials is greatly improved. Among these materials, GO/Fe-VO4-BIPY-1 has the most prominent performance, with a specific capacitance of 190 F g-1at 0.5 A g-1, which is attributed to the excellent synergistic effect between the Faraday chemical reaction and electric double-layer capacitance. In comparison with pristine Fe-VO4-BIPY, GO/Fe-VO4-BIPY-1 delivers more excellent surface area and therefore exhibits abundant redox reaction sites, achieving better electrochemical performance the best. After assembly with the positive Ni(OH)2electrode, the maximum energy density of 46.84 W h kg-1at a power density of 850 W kg-1is achieved.