Zheng Lingxia, Guan Lingtong, Yang Guang, Chen Sanming, Zheng Huajun
Department of Applied Chemistry, Zhejiang University of Technology Hangzhou 310032 China
State Key Laboratory Breeding Base of Green Chemistry Synthesis Technology, Zhejiang University of Technology Hangzhou 310032 China.
RSC Adv. 2018 Feb 26;8(16):8607-8614. doi: 10.1039/c8ra00285a. eCollection 2018 Feb 23.
CoFeO/reduced graphene oxide (CoFeO/rGO) hydrogel was synthesized a facile one-pot solvothermal approach. The three-dimensional (3D) network structure consists of well-dispersed CoFeO nanoparticles on the surfaces of graphene sheets. As a binder-free electrode material for supercapacitors, the electrochemical properties of the CoFeO/rGO hybrid hydrogel can be easily adjusted by changing the concentration of the graphene oxide (GO) precursor solution. The results indicate that the hybrid material made using 3.5 mg mL GO solution exhibits an outstanding specific capacitance of 356 F g at 0.5 A g, 68% higher than the pure CoFeO counterpart (111 F g at 0.5 A g), owing to the large specific surface area and good electric conductivity. Additionally, an electrochemical energy storage device based on CoFeO/rGO and rGO was assembled, which exhibits a high energy density of 17.84 W h kg at a power density of 650 W kg and an excellent cycling stability with 87% capacitance retention at 5 A g after 4000 cycles. This work takes one step further towards the development of 3D hybrid hydrogel supercapacitors and highlights their potential application in energy storage devices.
通过简便的一锅溶剂热法合成了CoFeO/还原氧化石墨烯（CoFeO/rGO）水凝胶。三维（3D）网络结构由石墨烯片表面均匀分散的CoFeO纳米颗粒组成。作为超级电容器的无粘结剂电极材料，CoFeO/rGO混合水凝胶的电化学性能可通过改变氧化石墨烯（GO）前驱体溶液的浓度轻松调节。结果表明，使用3.5 mg mL GO溶液制备的混合材料在0.5 A g下表现出356 F g的出色比电容，比纯CoFeO对应物（0.5 A g下为111 F g）高68%，这归因于其大比表面积和良好的导电性。此外，组装了基于CoFeO/rGO和rGO的电化学储能装置，该装置在功率密度为650 W kg时表现出17.84 W h kg的高能量密度，并且在4000次循环后，在5 A g下具有出色的循环稳定性，电容保持率为87%。这项工作朝着3D混合水凝胶超级电容器的发展又迈进了一步，并突出了它们在储能装置中的潜在应用。
