金属氧化物复合材料的燃烧法制备及赝电容性能研究

发布时间：2018-03-05 18:30

本文选题：超级电容器　切入点：燃烧法　出处：《太原理工大学》2017年硕士论文　论文类型：学位论文

【摘要】：随着社会的进步和发展,开发新型能源存储设备成为缓解甚至解决当前面临诸多问题的有效途径,超级电容器作为一种新型储能设备成为当前研究的热点,有望在汽车、军事、未来电网及消费类电子产品等领域中获得广泛应用。随着超级电容器材料的研究日渐深入,各种电极材料层出不穷,其中金属氧化物类材料以较高的比电容、良好电化学稳定性成为一类具有广阔应用前景的电极材料。目前,通过多种方法均能制备出该类金属氧化物,但大多制备过程繁杂或者产率较低,严重制约了这类材料的发展。本论文采用燃烧法大量合成了MnCo_2O_4,MnO2/Mn Co_2O_4和Ni O/C/CNTs金属氧化物及其复合材料,并研究了其赝电容性能。主要研究过程及结论如下:(1)以Mn(NO_3)_2、Co(NO_3)_2·6H2O和甘氨酸为原料,通过溶液燃烧法,成功制备了MnCo_2O_4。研究了前驱混合溶液中金属离子(Mn2+:Co2+为1:2)与甘氨酸之比对材料的形貌和赝电容性能的影响。经过XRD、SEM和电化学测量等测试表明,不同的金属离子/甘氨酸摩尔比对材料的颗粒尺寸和电化学性能具有较大影响。当Mn2+:Co2+:甘氨酸的摩尔比为1:2:14/9时,材料的颗粒最小,电化学性能也最优。当电流密度为0.5和10 A/g时,其比电容分别达到458和300 F/g。(2)通过溶液燃烧法制备大量多孔MnO2/MnCo_2O_4复合材料。在上述最佳金属离子/甘氨酸摩尔比的基础上,保持其比例不变,研究前驱混合溶液中Mn2+与Co2+摩尔比的变化对复合材料形貌和电化学性能的影响。研究证明,前驱混合溶液中Mn2+/Co2+摩尔比对材料的颗粒大小、粗糙程度、孔径分布和孔洞疏密程度都有较大影响。电化学测试表明,当Mn2+:Co2+摩尔比为3:4时,MnO2/MnCo_2O_4复合材料取得最佳的赝电容性能。当电流密度为0.5 A/g时,比电容达到497 F/g;当电流密度增加到10 A/g时,其比电容为312 F/g。在5 A/g的电流密度下经过5000次恒流充放电后,其比电容量仍能保持60%。(3)以Ni(NO_3)_2·6H2O和尿素为原料,用燃烧法大量合成多孔的NiO/C复合材料,并研究了不同的热处理过程对复合材料电化学性能的影响。前驱混合溶液中Ni2+和尿素的摩尔比为1:6。研究表明,前驱体溶液先升温至240°C保温0.5 h后再继续升温至350°C保温1 h的热处理方式获得最佳的电化学性能。为进一步提高材料性能,通过在前驱混合溶液中加入一定量的CNTs,制备了NiO/C/CNTs复合材料,当电流密度为1 A/g时,其比电容提高到1618 F/g。以NiO/C/CNTs复合材料为阳极,活性炭为阴极制备成非对称性电容器,在0.2 A/g时的比电容达到83 F/g,相应的能量密度为93.4Wh/kg,功率密度为0.6 kW/kg。在3 A/g的电流密度下经过1500次循环充放电,比电容保持约40%。
[Abstract]:With the social progress and development, the development of new energy storage equipment has become the effective way to ease or even solve the many problems facing the supercapacitor is a new energy storage equipment has become a research hotspot, is expected in the automotive, military, widely used future power grid and consumer electronics and other fields. With the Research of super capacitor the material used is deepening, all emerge in an endless stream electrode material, wherein the metal oxide materials with high specific capacitance, good electrochemical stability as electrode material for a class that has a broad application prospect. At present, through a variety of methods could be prepared by this kind of metal oxide, but most of the preparation process of complex and the yield is low, serious restrict the development of this kind of material. In this paper a large number of MnCo_2O_4 were synthesized by combustion method, MnO2/Mn Co_2O_4 and Ni O/C/CNTs metal oxide and its composite material The material, and studied its pseudocapacitive performance. The main research process and conclusions are as follows: (1) to Mn (NO_3) _2, Co (NO_3) _2 - 6H2O and glycine as raw materials by solution combustion method, MnCo_2O_4. was prepared successfully on the metal ion precursor mixed solution (Mn2+ Co2+ 1:2) influence of morphology and pseudocapacitive performance of materials with glycine. After comparison of XRD, SEM and electrochemical measurement test show that the metal ions / different particle size and electrochemical properties of glycine molar ratio of materials has a great influence. When Mn2+: Co2+: Glycine molar ratio was 1:2:14/9, the minimum particle material, electrochemical performance also the best. When the current density is 0.5 and 10 A/g, the specific capacitance reached 458 and 300 F/g. (2) were prepared by a large number of porous MnO2/MnCo_2O_4 composites by solution combustion. Based on the above optimum molar ratio of glycine / metal ions, maintain its The proportion unchanged, changes of Mn2+ and Co2+ molar ratio of precursor in the mixed solution and the electrochemical properties of composite materials. The morphology study shows that precursor in the mixed solution of Mn2+/Co2+ molar ratio on the material particle size, roughness, have great influence on the pore size distribution and pore density. The electrochemical tests show that when the molar ratio of 3:4: Co2+ Mn2+ when the MnO2/MnCo_2O_4 composite material has a pseudocapacitive performance best. When the current density is 0.5 A/g, the specific capacitance reaches 497 F/g; when the current density increased to 10 A/g, the specific capacitance is 312 F/g. at the current density of 5 A/g after 5000 charge discharge, it still maintains a 60%. capacitance the amount of (3) to Ni (NO_3) _2, 6H2O and urea as raw materials, NiO/C composite material for a large number of synthetic porous combustion method, and studied the effects of different heat treatment process on the electrochemical properties of the composite precursor mixed. The molar ratio of Ni2+ and urea in solution for 1:6. study showed that the precursor solution is first heated to 240 DEG C after holding for 0.5 h further heating to 350 DEG C 1 H insulation heat treatment to obtain the best electrochemical performance. In order to further improve the performance, by adding a certain amount of the precursor in the mixed solution of CNTs and NiO/C/CNTs the composite material was prepared, when the current density is 1 A/g, the specific capacitance increased to 1618 F/g. with NiO/C/CNTs composite as anode and activated carbon as cathode prepared by asymmetric capacitor at 0.2 A/g the specific capacitance of 83 F/g, the corresponding energy density is 93.4Wh/kg, the power density is 0.6 kW/kg. at the current density of 3 A/g after 1500 cycles, the specific capacitance of about 40%.

【学位授予单位】：太原理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TB33;TM53

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