共查询到17条相似文献,搜索用时 171 毫秒
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以焦粉为原料,用HNO3预处理除灰,采用KOH浸渍-煅烧活化法制备焦粉活性炭(CPAC),通过场发射扫描电子显微镜、X射线衍射等表征其形貌,采用BET测试其比表面积、孔结构及孔径分布。初步考察了活化温度、活化时间等对焦粉活性炭电极材料电化学性能的影响。采用共沉淀法制备CPAC/Al-Ni(OH)2复合电极材料,通过恒电流充放电测试及循环伏安测试表征CPAC/Al-Ni(OH)2复合电极材料的电化学性能。结果表明,当活化温度为800℃、活化时间为3 h制得的焦粉活性炭电极材料的电化学性能最佳,比电容达到211 F/g。CPAC-800℃-3 h/Al-Ni(OH)2复合电极材料随Al掺杂量的增大呈现先增大后减小的趋势。在固定Al质量掺杂量为4%,炭镍质量比为1∶1时所得复合材料的比电容量最大:1173.6 F/g。恒电流充放电及循环伏安测试表明Al掺杂量为4%、炭镍比为1∶1的复合材料具有较好的电化学性能。 相似文献
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以氯化钴为原料,聚乙烯吡咯烷酮(PVP)为分散剂,采用化学沉淀的方法制备出由纳米粒子组成的片状α-Co(OH)2.用红外光谱对所制样品的组分进行分析,用X射线衍射和场发射扫描电子显微镜表征产物的结构和形貌,用循环伏安和恒电流充放电等测试方法对其电化学性能进行研究.研究结果表明,由纳米粒子组成的片状α-Co(OH)2表现出优良的电化学性能,单电极比电容高达1220 F/g. 相似文献
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以无模板法制备了泡沫镍载Co(OH)2纳米线电极,利用扫描电镜(SEM)和透射电镜(TEM)观测了纳米线的表面形貌,利用X射线衍射(XRD)分析了Co(OH)2纳米线的结构,通过循环伏安、恒流充放电和交流阻抗测试了电极的电化学电容性能.结果表明:Co(OH)2呈线状生长,其直径约为300nm,长度约为8~10μm,密集地生长在泡沫镍骨架上.电流密度为10mA·cm-2时电极的放电比容量高达677F·g-1,循环500次后比容量仍保持在574F·g-1,电化学阻抗测试其电荷传递电阻仅为0.23Ω,500次循环后电荷传递电阻仅增加0.03Ω. 相似文献
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为了改善Ni(OH)2的电化学性质,提高锌镍电池的充放电性能,用化学共沉淀法合成了混合铝镍氢氧化物Ni/Al(OH)x.用XRD和FTIR表征了Ni/Al(OH)x样品的晶体结构及IR光谱特征;测试了用Ni/Al(OH)x为正极活性物质的Zn/Ni实验电池的充放电性能.研究结果表明:所合成的Ni/Al(OH)x具有α-Ni(OH)2的晶体结构;Ni/Al(OH)x活性物质在充放电过程中主要为γ/α循环,以Ni/Al(OH)x作为正极活性物质的Zn/Ni试验电池具有优良的循环性能,其最高放电比容量为379mA·h/g. 相似文献
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通过高温碳化聚吡咯纳米管制备了氮掺杂碳纳米管(N-CNTs), 并采用共沉淀法将镍钴层状双氢氧化物(NiCo-LDH)原位生长在N-CNTs上, 制备出具有三维互联网状结构的N-CNTs/NiCo-LDH复合材料. 研究了镍钴摩尔比对N-CNTs/NiCo-LDH复合材料形貌结构和电化学性能的影响. 结果表明, 当镍钴摩尔比为1∶2时, N-CNTs/Ni1Co2-LDH具有最佳的电化学性能. 在1 A/g电流密度下, 其比电容可达1311.8 F/g; 当电流密度为 10 A/g时, 电容保持率高达88.3%, 展现出优异的倍率性; 在经过2500次循环后, 电容保持率仍可达76.4%, 具有良好的循环稳定性.由N-CNTs/Ni1Co2-LDH与活性炭(AC)电极所构建的N-CNTs/Ni1Co2-LDH//AC水系混合型超级电容器, 在750 W/kg功率密度下, 具有27.19 W·h/kg的高能量密度. 相似文献
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以化学法合成Li(Ni1/3Co1/3Mn1/3)1-xAlxO2系列正极材料(0≤x≤0.1);用X射线衍射仪、扫描电子显微镜和充放电仪研究系列产物的晶体微观结构、表面形貌以及电化学性能,研究不同Al含量参杂对材料性能的影响。结果表明,合成的材料均属于六方晶系,R3m空间群,保持α-NaFeO2层状结构相;Li(Ni1/3Co1/3Mn1/3)0.95Al0.05O2的首次放电容量166.30 mA·h/g,在2.5~4.5 V区间60次循环后比容量衰竭率为4.43%。通过对比Li(Ni1/3Co1/3Mn1/3)0.95Al0.05O2和Li(Ni1/3Co1/3Mn1/3)O2的电极阻抗,分析它们的电化学循环机理,可知掺杂Al后的正极材料适合大倍率放电。 相似文献
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以Co(NO_3)_2·6H_2O和Ni(NO_3)_2·6H_2O为钴源和镍源,采用溶剂热法一步合成了Co(OH)_2/Ni(OH)_2复合材料,通过煅烧该复合材料可得到NiCo_2O_4。采用XRD、SEM、BET等对材料进行了表征,结果表明,Co(OH)_2/Ni(OH)_2复合材料是薄片组成的花状形貌,比表面积为37. 48m~2/g。电化学性能测试表明,Co(OH)_2/Ni(OH)_2复合材料比NiCo_2O_4具有更高的比电容值和容量保持率。在0. 5A/g的电流密度下,复合材料比电容值可达到1097. 8F/g,而NiCo_2O_4比电容值仅为86. 1F/g。因此,与煅烧后的NiCo_2O_4材料相比,Co(OH)_2/Ni(OH)_2复合材料具有更加优良的电化学性能,这为高性能超级电容器材料的制备提供了一个新思路。 相似文献
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《Arabian Journal of Chemistry》2022,15(4):103718
The present study attempts to prepare Al-substituted α-Ni(OH)2 and Al-substituted α-Ni(OH)2 with modified interlayer anions by directly immersing pure α-Ni(OH)2 into AlCl3-containing solutions. XRD and FT-IR analysis demonstrated Al-substituted α-Ni(OH)2 can be prepared directly by soaking pure α-Ni(OH)2 into AlCl3 solution. Al-substituted α-Ni(OH)2 with S2O32? as the primary anion in the interlayer can be obtained by immersing pure α-Ni(OH)2 into AlCl3-Na2S2O3 solution. The analysis of Al content in samples demonstrated the Al content in the Al-substituted α-Ni(OH)2 was regulated by adjusting the molar ratio of pure α-Ni(OH)2 soaked in the solution and Al3+ dissolved in the solution. The Al element entered the lattice of pure α-Ni(OH)2 through a process of pure α-Ni(OH)2 dissolved followed by the precipitation of Al3+, Ni2+ and OH?. The S2O32? entered the interlayer of Al-substituted α-Ni(OH)2 through the formation process of the Al-substituted α-Ni(OH)2 or though ion exchange with the intercalated Cl?. The strongly alkaline solution soaking results demonstrated that Al-substituted α-Ni(OH)2 prepared by soaking pure α-Ni(OH)2 into AlCl3-containing solutions could preliminary get stabilized in the strongly alkaline solution. 相似文献
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采用AAO模板及后处理方法合成了圆盘状α-Co(OH)2并研究了其电化学电容性能. 在该合成方法中, 先采用阳极氧化铝模板结合交流电沉积的方法获得钴纳米线, 而后将其在碱液中通过溶解氧氧化生成终端产物. 用红外光谱(FT-IR), X射线衍射(XRD)和场发射扫描电子显微镜(FE-SEM)表征了产物的结构和形貌; 用循环伏安、恒电流充放电测试方法对其电化学性能进行了测试. 此外, 对圆盘状Co(OH)2的形成机理进行了初步探讨. 结果表明, 用此方法合成的Co(OH)2具有圆盘状形貌, 属α相态, 且表现出较好的电容特性. 相似文献
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《Electrochemistry communications》2007,9(9):2315-2319
A high specific capacitance was obtained for α-Co(OH)2 potentiostatically deposited onto a stainless-steel electrode in 0.1 M Co(NO3)2 electrolyte at −1.0 V vs. Ag/AgCl. The structure and surface morphology of the obtained α-Co(OH)2 were studied by using X-ray diffraction analysis and scanning electron microscopy. A network of nanolayered α-Co(OH)2 sheets was obtained; the average thickness of individual α-Co(OH)2 sheets was 10 nm, and the thickness of the deposit was several micrometers. The capacitive characteristics of the α-Co(OH)2 electrodes were investigated by means of cyclic voltammetry and constant current charge–discharge cycling in 1 M KOH electrolyte. A specific capacitance of 860 F g−1 was obtained for a 0.8 mg cm−2 α-Co(OH)2 deposit. The specific capacitance did not decrease significantly for the active mass loading range of 0.1–0.8 mg cm−2 due its layered structure, which allowed easy penetration of electrolyte and effective utilization of electrode material even at a higher mass. This opens up the possibility of using such materials in supercapacitor applications. 相似文献
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M. Y. Wu J. M. Wang J. Q. Zhang C. N. Cao 《Journal of Solid State Electrochemistry》2006,10(6):411-415
The effects of manganese on the structure and electrochemical performance of Al-substituted α-Ni(OH)2 prepared by a chemical co-precipitation method were studied. The results of XRD and IR showed that the Al-substituted Ni(OH)2 with various Mn contents are typical α-phase. The Mn-free sample is labile in alkaline media and partly converted to β-Ni(OH)2. The stability of the samples improves with the increase in Mn content. The results of galvanostatic charge-discharge experiments
showed that the addition of Mn increases the difference between the oxygen evolution and charge potentials, which improves
the charge efficiency and increases the discharge capacity. The Mn-containing samples display better cycle stability than
the Ni/Al sample without Mn. The Al-substituted Ni(OH)2 sample with Mn 9.3% shows the highest discharge capacity during the whole cycle, and the largest discharge capacity is 260 mAh g−1 .The electrochemical transfer resistance (R
t) value decreases with the increase of Mn content. 相似文献
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《中国化学快报》2021,32(8):2453-2458
In power storage technology,ion exchange is widely used to modify the electronic structures of electrode materials to stimulate their electrochemical properties.Here,we proposed a multistep ion exchange(cation exchange and anion exchange) strategy to synthesize amorphous Ni-Co-S and β-Co(OH)_2 hybrid nanomaterials with a hollow polyhedron structures.The synergistic effects of different components and the remarkable superiorities of hollow structure endow Ni-Co-S/Co(OH)_2 electrode with outstanding electrochemical performance,including ultra-high specific capacity(1440.0 C/g at 1 A/g),superior capacitance retention rate(79.1% retention at 20 A/g) and long operating lifespan(81.4% retention after5000 cycles).Moreover,the corresponding hybrid supercapacitor enjoys a high energy density of 58.4 Wh/kg at the power density of 0.8 kW/kg,and a decent cyclability that the capacitances are maintained at80.8% compared with the initial capacitance.This research presents a high-performance electrode material and provides a promising route for the construction of electrode materials for supercapacitors with both structural and component advantages. 相似文献
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Jun-Wei Lang Ling-Bin Kong Min Liu Yong-Chun Luo Long Kang 《Journal of Solid State Electrochemistry》2010,14(8):1533-1539
In this work, stabilized Al-substituted α-Ni(OH)2 materials were successfully synthesized by a chemical coprecipitation method. The experimental results showed that the 7.5% Al-substituted α-Ni(OH)2 materials exhibited high specific capacitance (2.08?×?103 F/g) and excellent rate capability due to the high stability of Al-substituted α-Ni(OH)2 structures in alkaline media, suggesting its potential application in electrode material for supercapacitors. To enhance energy density, an asymmetric type pseudo/electric double-layer capacitor was considered where α-Ni(OH)2 materials and activated carbon act as the positive and negative electrodes, respectively. Values for the maximum specific capacitance of 127 F/g and specific energy of 42 W·h/kg were demonstrated for a cell voltage between 0.4 and 1.6 V. By using the α-Ni(OH)2 electrode, the asymmetric supercapacitor exhibited high energy density and stable power characteristics. The hybrid supercapacitor also exhibited a good electrochemical stability with 82% of the initial capacitance over consecutive 1,000 cycle numbers. 相似文献