三维多孔镍复合电极的制备及其电化学性能研究

发布时间：2018-02-25 05:18

本文关键词： 超级电容器多孔镍阳极氧化铝循环伏安　出处：《华南理工大学》2014年硕士论文　论文类型：学位论文

【摘要】：人类社会正面临能源紧缺和环境污染的挑战，新型能源材料和储能材料成为了世界各国科学重要发展方向。作为一种新型储能材料，电化学超级电容器材料由于具有高充放电速率和长循环寿命等优点，而引起各国政府和科学家广泛关注。其中，，NiO/Ni(OH)2由于具有超高的比电容（理论电容值是3750F/g），对环境无污染以及价格低廉等优势，而成为最有潜力的超级电容器电极材料之一。本论文突破电极材料传统制备方法的束缚，将模板法和循环伏安生长法相结合制备三维连通氢氧化镍/镍复合电极，并通过调节复合电极微结构及成分，探索制备高性能电化学超级电容电极材料的有效途径。本论文首先通过阳极氧化腐蚀铝制备了大比表面积多孔铝，并通过电铸复型多孔铝获得了三维结构多孔镍材料，最后获得了高性能三维氢氧化镍/镍复合电极材料。实验结果表明：采用电化学氧化还原循环法在-1.5V~-0.2V之间对多孔镍进行粗糙化处理，可以获得大比表面积的多孔镍；对粗糙多孔镍在0V~0.5V之间采用电化学原位生长法制备Ni(OH)2，经过XRD测试表明活性物质的主要成分是α-Ni(OH)2；电化学性能测试表明，多孔Ni(OH)2/Ni复合电极具有很高的体积比电容(1559F/cm3)和很大的面积比电容(7.01F/cm2)(扫描速率为1mV/s)，该复合电极同时具有优异的循环稳定性，在扫描速率为10mV/s循环测试500次后，其容量的保持率达到93%。本论文通过周期性阳极氧化和化学腐蚀相结合制备了三维互联层状结构的阳极氧化铝光子晶体模板，并采用电铸工艺进行复型得到了层状纳米结构多孔镍集流体，然后采用循环伏安法原位生长获得多孔α-Ni(OH)2/Ni复合电极。对50层三维多孔Ni(OH)2/Ni复合电极进行恒流充放电测试(5mA/cm2)，获得了超高的体积比电容(1387F/cm3)和很大的面积比电容(2.51F/cm2)，同时也表现出了优秀的循环稳定性，在扫描速率为10mV/s循环寿命测试1000次之后，容量几乎没有任何的衰减。层状复合电极具有优异电化学性能的主要原因是优化的多孔纳米微结构提高了电极材料的比表面积，而超薄的活性物质层提高了电极材料的有效利用率。
[Abstract]:Human society is facing the challenge of energy shortage and environmental pollution. New energy materials and energy storage materials have become an important development direction of science all over the world. Electrochemical supercapacitor materials have the advantages of high charge / discharge rate and long cycle life. Among them, nio / nio / nio / nio / nio / nio / nio / nio / nio / nio / Nio / Nio / Nio / Nio / Nio / NiOHH2 has the advantages of high specific capacitance (the theoretical capacitance is 3750F / g), no pollution to the environment and low price. In this paper, the template method and cyclic voltammetry (CV) method are combined to prepare three dimensional connected nickel hydroxide / nickel composite electrode, which is one of the most promising electrode materials for supercapacitor. By adjusting the microstructure and composition of the composite electrode, an effective way to prepare high performance electrochemical supercapacitor electrode material was explored. In this paper, porous aluminum with large specific surface area was prepared by anodic oxidation of aluminum, and three dimensional porous nickel material was obtained by electroforming porous aluminum. Finally, high performance three dimensional nickel hydroxide / nickel composite electrode materials were obtained. The experimental results show that porous nickel with large specific surface area can be obtained by roughening porous nickel between -1.5 V and -0.2 V by electrochemical redox cycle method. The coarse porous nickel was prepared by electrochemical in-situ growth method between 0 V and 0.5 V. The XRD test showed that the main component of the active substance was 伪 -NiOH2, and the electrochemical performance test showed that the main composition of the active material was 伪 -NiOH2. The porous Ni(OH)2/Ni composite electrode has a high volume specific capacitance of 1559F / cm ~ (3) and a large area specific capacitance of 7.01F / cm ~ (-2) (scan rate is 1 MV / s). The composite electrode also has excellent cycling stability. After 500 cycles of scanning rate of 10 MV / s, the capacity retention rate of the composite electrode is 93%. In this paper, the anodic aluminum oxide photonic crystal template with three dimensional interconnected layered structure was prepared by the combination of periodic anodic oxidation and chemical corrosion, and the porous nickel collector with layered nanostructure was obtained by electroforming process. Then the porous 伪 -NiOHH / 2 / Ni composite electrode was obtained by in situ growth by cyclic voltammetry. The constant current charge-discharge test of 50 layers of three-dimensional porous Ni(OH)2/Ni composite electrode was carried out, and the ultra-high volume specific capacitance of 1387F / cm _ 3 and a large area specific capacitance of 2.51F / cm _ 2 were obtained. Showing excellent cyclic stability, After 1000 cycles at a scanning rate of 10 MV / s, the capacity of the layered composite electrode has almost no attenuation. The main reason for the excellent electrochemical performance of the layered composite electrode is that the optimized porous nanostructure increases the specific surface area of the electrode material. The effective utilization ratio of electrode material was improved by the thin active material layer.
【学位授予单位】：华南理工大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TM53

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