共查询到20条相似文献,搜索用时 62 毫秒
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采用液相共沉淀法制备了一种含Mn、S、O的无定型粉末材料,元素分析结果表明其组成为MnS0.4O0.8。采用XRD、SEM对其进行了物理表征。通过循环伏安和恒流充放电研究了其电容行为。结果表明:在1mol.L-1Na2SO4溶液中该材料具有良好的电容性能。当扫描速度为2mV.s-1时,其比电容为131F.g-1,经历500循环后其比电容还能保持初始值的94.8%,表现了良好的稳定性。恒流充放电实验结果表明材料的可逆性良好。此材料可作为电化学超级电容器的一种新的候选材料。 相似文献
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神华烟煤活化制备电化学电容器电极材料的研究 总被引:1,自引:0,他引:1
以神华烟煤为前驱体,KOH为活化剂制备高比表面积活性炭。采用N_2吸附法对活性炭的比表面积、孔容和孔结构进行了表征,并评价了其用作超级电容器电极材料的电化学特性。在碱炭比为4:1,800℃活化1 h的条件下制备的活性炭比表面积达3 134.28 m~2·g~(-1),总孔容1.96 cm~3·g~(-1),中孔率87.94%。该活性炭在3 mol/L KOH水溶液及1 mol/L(C_2H_5)_4NBF_4/碳酸丙烯酯(Propylene carbonate PC)电解液中均具有高的比电容(分别为281 F·g~(-1),155 F·g~(-1))和低的等效串联内阻。 相似文献
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选择板栗壳为碳源(CC),碳化后用KOH活化,制得CC700-OH。对其形貌和性能进行了SEM、TEM、XRD以及BET等表征与测试,发现CC700-OH具有孔/片穿插的夹心结构,在1 A/g时比电容为540 F/g,循环6000圈后比电容仍可保持初始值的98%。在二电极体系中,组装CC700-OH//CC700-OH对称电容器,该对称电容器在1 A/g的比电容为106 F g-1,电势窗口宽0~1.6 V,首次库伦效益为0.52。功率密度为800 mW/g时,能量密度为37.3 mW•h/g,当功率密度增加至12000 mW/g时,能量密度仍可为23 mW•h/g。以上研究结果表明用板栗壳作为碳源制备对称性超级电容器电极材料是可行的。 相似文献
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《Ceramics International》2023,49(5):7266-7273
Polyethylene terephthalate (PET), the traditional material for polyester food packaging, is difficult to degrade. Taking PET-like plastics as carbon source, this study fabricates cobalt oxide (Co3O4)/carbon composites with flake structure through carbonization and solvothermal synthesis, which can serve as a useful supercapacitor electrode. Then, the electrochemical properties of samples were investigated under different heating time of solvothermal synthesis. Experiments show that the heating time of solvothermal synthesis had a certain impact on the electrical capacity and charging/discharging performance of the composites. Among the samples, SL-8 stands out with an electrical capacity of 110.8 F g?1, the retention reached 88.82% after 2000 cycles. This composite offers a promising electrode material for supercapacitors, and sheds new lights on solving white pollution. 相似文献
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An efficient active material for supercapacitor electrodes is prepared by reacting potassium hydroxide (KOH) with graphene oxide followed by chemical reduction with hydrazine. The electrochemical performance of KOH treated graphene oxide reduced for 24 h (reduced chemically modified graphene oxide, RCMGO-24) exhibits a specific capacitance of 253 F g-1 at 0.2 A g-1 in 2 M H2SO4 compared to a value of 141 F g-1 for graphene oxide reduced for 24 h (RGO-24), and good cyclic stability up to 3,000 cycles. Interestingly, RCMGO-24 demonstrated a higher specific capacitance and excellent cycle stability due to its residual oxygen functional groups that accelerate the faradaic reactions and aid in faster wetting. This non-annealed strategy offers the potential for simple and cost-effective preparation of an active material for a supercapacitor electrode. 相似文献
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介绍了碳材料、金属氧化物和导电聚合物及其复合材料等超级电容器电极材料的研究现状,并指出其发展方向是制备性能优异的复合材料和实现材料纳米化。 相似文献
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Commercial nanoporous carbon RP-20 was activated with water vapor in the temperature range from 950 °C to 1150 °C. The XRD analysis was carried out on nanoporous carbon powder samples to investigate the structural changes (graphitisation) in modified carbon that occurred at activation temperatures T ? 1150 °C. The first-order Raman spectra showed the absorption peak at 1582 cm−1 and the disorder (D) peak at 1350 cm−1. The low-temperature N2 adsorption experiments were performed at −196 °C and a specific surface area up to 2240 m2g−1 for carbon activated at T = 1050 °C was measured. The cell capacitance for two electrode activated nanoporous carbon system advanced up to 60 F g−1 giving the specific capacitance ∼240 F g−1 to one electrode nanoporous carbon ∣1.2 M (C2H5)3CH3NBF4 + acetonitrile solution interface. A very wide region of ideal polarisability for two electrode system (∼3.2 V) was achieved. The low frequency limiting specific capacitance very weakly increases with the rise of specific area explained by the mass transfer limitations in the nanoporous carbon electrodes. The electrochemical characteristics obtained show that some of these materials under discussion can be used for compilation of high energy density and power density non-aqueous electrolyte supercapacitors with higher power densities than aqueous supercapacitors. 相似文献
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以煤系针状焦生焦为原料,KOH为活化剂,制备了用于超级电容器电极材料的活性炭。以3 mol/L KOH为电解液,用三电极电化学系统测试了活性炭的电化学性质;考察了活化剂用量对活性炭电化学性质的影响。研究结果表明:活化过程中,随着碱含量的增加,活性炭的电化学性能逐渐提高。当碳碱比为1∶3时,活性炭的比表面积达到2572.7 m2/g;电流密度为1 A/g时,其质量比电容达到316 F/g。循环5000圈之后,比电容保持在95.7%,库仑效率保持在97.0%。采用两电极系统,进一步考察了活性炭的电化学性能,以1 mol/L Na2SO4为电解液,电压窗口拓宽至1.8 V,循环伏安曲线同样展现出良好的矩形,能量密度和功率密度分别为20.8 W·h/kg和230 W/kg。 相似文献