钴酸镍及其复合材料的制备和电化学性能的研究

发布时间：2018-04-10 16:31

本文选题：超级电容器 + 钴酸镍　；参考：《江苏大学》2017年硕士论文

【摘要】：超级电容器作为新式储能设备研究热点,电极材料的性质对超级电容器性能起决定性作用,因此电极材料的研究是科研方面的重中之重。过渡金属氧化物具有资源丰富,环境友好且电化学性能突出等优点而成为人们的重点研究对象。本文以镍、钴金属氧化物为研究对象,探索了合成条件,不同镍钴比例和碳材料进行复合以及以金属有机骨架ZIF-67为模板合成各向非异性的特殊结构对材料结构,电化学性能,倍率性能和循环稳定性的影响,内容如下:1.以水热法结合煅烧来制备Ni Co_2O_4,探索合成条件对材料结构和形貌的影响并研究其电化学性能,倍率性能和循环稳定性。结果表明,以去离子水和乙二醇为溶剂体系,利用六亚甲基四胺(HMT)在高温下能够缓慢的释放OH-的特性制备分层介孔NiCo_2O_4纳米线在1 A·g~(-1)的电流密度下表现出2876 F·g~(-1)的高比电容,随着电流密度增加到10.0A·g~(-1),比电容仍然可以保持1290 F·g~(-1),这意味着电极材料良好的大电流放电能力。此外,比电容保持率在500次循环后达到84.7%。这表明了此电极材料优异的循环性能。分层介孔的NiCo_2O_4的出色电化学性能表明其有作为超级电容器的电极材料的潜力。2.采用溶剂热法结合水热法,以PVP作为表面活性剂,六亚甲基四胺(HMT)不但能够提供氮源,和能够当作沉淀剂和还原剂制备NiCo_2O_4/N-rGO纳米复合材料,经过热退火后结构不发生改变,复合材料的比表面积可以达到99.38 m2 g~(-1),在1 A·g~(-1)的电流密度下具有2090 F·g~(-1)的高比电容,而当电流密度达到10 A·g~(-1)时仍保持1257.5 F·g~(-1)的高比电容,显示出了材料的高倍率性能,同时在2000次恒电流充放电循环后,电容保持率为60.16%。这项研究表明NiCo_2O_4/N-rGO纳米复合材料作为超级电容器的电极材料具有高活性,大比电容和良好的倍率性能。3.以金属有机骨架为牺牲模板,利用离子的共沉淀作用制备中空NiCo_2O_4@ZnCo_2O_4@Co_3O_4纳米笼复合材料,利用骨架中有机配体经过高温煅烧可有效阻止金属的团聚,能够得到大小均匀的金属氧化物纳米笼复合材料,这种独特结构的复合材料具有复杂的壳体,表面呈现多孔隙的网络状结构,能够提供更多的活性位点,促进电极材料的氧化还原反应。在1 A·g~(-1)和10 A·g~(-1)的电流密度下分别展现1892.5 F·g~(-1)和1135 F·g~(-1)的高比电容,显示出了材料的高倍率性能,同时经过2000次充放电循环后显示出66%的电容保持率,具有良好的循环稳定性。此次研究能够对其它复合材料的合成提供思路,为构造更加理想的电极材料提供了更多可能性。
[Abstract]:Supercapacitor as a new energy storage equipment research hotspot, the properties of electrode materials play a decisive role in the performance of supercapacitors, so the research of electrode materials is the most important in scientific research.Transition metal oxide (TME) has become an important research object due to its advantages of rich resources, environmental friendliness and outstanding electrochemical performance.In this paper, nickel and cobalt metal oxides were used as the research objects. The synthesis conditions were explored, the different ratios of nickel and cobalt and the carbon materials were recombined, and the special structure and electrochemical properties of the materials were synthesized by using the metal-organic skeleton ZIF-67 as the template.The effect of rate performance and cyclic stability is as follows: 1.NiCo2O4 was prepared by hydrothermal method combined with calcination. The effects of synthesis conditions on the structure and morphology of the material were investigated. The electrochemical performance, rate performance and cyclic stability were studied.With the increase of current density to 10.0A / g ~ (-1), the specific capacitance can still be kept at 1290 F / g ~ (-1), which means that the electrode material has a good high current discharge capacity.In addition, the specific capacitance retention rate reached 84.7 after 500 cycles.This indicates the excellent cycling performance of the electrode material.The excellent electrochemical performance of layered mesoporous NiCo_2O_4 indicates its potential as electrode material for supercapacitors.At the same time, after 2000 constant current charge-discharge cycles, the capacitance retention rate is 60.16.This study shows that NiCo_2O_4/N-rGO nanocomposites as electrode materials for supercapacitors have high activity, large specific capacitance and good rate performance.Hollow NiCo_2O_4@ZnCo_2O_4@Co_3O_4 nanocage composites were prepared by ion coprecipitation using organometallic skeleton as sacrificial template. The high temperature calcination of organic ligands in the framework could effectively prevent metal agglomeration.This unique structure has complex shells, porous network structures, and can provide more active sites.Promote the redox reaction of electrode material.At the current density of 1 A g ~ (-1) and 10 A ~ (G ~ (-1)), the high specific capacitance of 1892.5 F / g ~ (-1) and 1135 F / g ~ (-1)) shows the high rate performance of the material. At the same time, after 2000 charge-discharge cycles, the capacitive retention rate is 66% and the cycle stability is good.This study can provide ideas for the synthesis of other composite materials and provide more possibilities for the construction of more ideal electrode materials.
【学位授予单位】：江苏大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TQ138.13;TB33

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