共查询到16条相似文献,搜索用时 15 毫秒
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《电子科技文摘》2006,(9)
0622723 NiO/AC非对称超级电容器的研究[刊,中]/庄凯//西华大学学报(自然科学版).—2006,26(1).—6-7,13 (G)通过热处理球形Ni(OH)_2得到NiO粉末,将其作为正极与活性炭(AC)负极组装成非对称超级电容器,用恒流充放电测试分析了超级电容器的电容特性。讨论了正负极活性物质比例、充放电电流和热处理时间对超级电容器比电容量、内阻的影响。结果表明:正负极活性物质比为1:3,工作电流密度为200mA/g,当Ni (OH)_2的热处理时间为2h,充电电压为1.3V时,超级电容器的双电极比电容量可达7.15F/g。参9 0622724一种新颖的串联超级电容器组的电压均衡方法[刊, 相似文献
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金属氧化物改性炭电极及EDLC性能研究 总被引:1,自引:0,他引:1
将市售活性炭用Ni(NO3)2及Co(NO3)2溶液浸渍后进行高温热解处理。采用BET、循环伏安、恒流充放电等测试手段,研究改性活性炭电极构成的双电层电容器(EDLC)性能。结果表明,由Ni(NO3)2及Co(NO3)2热解产生的NiO、CoO有显著的准电容效应,与活性炭原有的双电层电容构成了复合电容,因而改性炭的电容量有明显提高,质量比电容分别高达246.1,198.8 F/g,比原样炭的130.1 F/g分别提高了89.2%、52.8%。 相似文献
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将多组分活性材料组合成新的结构用作电极材料是提高超级电容器性能的一种有效措施。采用典型的两步水热法与电沉积法制备了FeCo2S4/Ni(OH)2复合纳米材料,并表征其物理及电化学性能。结果表明,FeCo2S4纳米花被电沉积上的Ni(OH)2纳米片包围,形成三维互连网状结构,有利于电极材料与电解液的充分接触。所得的FeCo2S4/Ni(OH)2复合电极材料显示出极高的比电容(当电流密度为1 A·g^-1时,比电容达1588.2 F·g^-1)、优异的倍率性能及循环稳定性。此外,以FeCo2S4/Ni(OH)2为正极、活性炭为负极组装了非对称超级电容器。结果显示,非对称超级电容器具有高能量密度及良好的循环稳定性。 相似文献
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The demand for advanced energy storage devices such as supercapacitors and lithium‐ion batteries has been increasing to meet the application requirements of hybrid vehicles and renewable energy systems. A major limitation of state‐of‐art supercapacitors lies in their relatively low energy density compared with lithium batteries although they have superior power density and cycle life. Here, we report an additive‐free, nano‐architectured nickel hydroxide/carbon nanotube (Ni(OH)2/CNT) electrode for high energy density supercapacitors prepared by a facile two‐step fabrication method. This Ni(OH)2/CNT electrode consists of a thick layer of conformable Ni(OH)2 nano‐flakes on CNT bundles directly grown on Ni foams (NFs) with a very high areal mass loading of 4.85 mg cm?2 for Ni(OH)2. Our Ni(OH)2/CNT/NF electrode demonstrates the highest specific capacitance of 3300 F g?1 and highest areal capacitance of 16 F cm?2, to the best of our knowledge. An asymmetric supercapacitor using the Ni(OH)2/CNT/NF electrode as the anode assembled with an activated carbon (AC) cathode can achieve a high cell voltage of 1.8 V and an energy density up to 50.6 Wh/kg, over 10 times higher than that of traditional electrochemical double‐layer capacitors (EDLCs). 相似文献
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Jun Yan Zhuangjun Fan Wei Sun Guoqing Ning Tong Wei Qiang Zhang Rufan Zhang Linjie Zhi Fei Wei 《Advanced functional materials》2012,22(12):2632-2641
Hierarchical flowerlike nickel hydroxide decorated on graphene sheets has been prepared by a facile and cost‐effective microwave‐assisted method. In order to achieve high energy and power densities, a high‐voltage asymmetric supercapacitor is successfully fabricated using Ni(OH)2/graphene and porous graphene as the positive and negative electrodes, respectively. Because of their unique structure, both of these materials exhibit excellent electrochemical performances. The optimized asymmetric supercapacitor could be cycled reversibly in the high‐voltage region of 0–1.6 V and displays intriguing performances with a maximum specific capacitance of 218.4 F g?1 and high energy density of 77.8 Wh kg?1. Furthermore, the Ni(OH)2/graphene//porous graphene supercapacitor device exhibits an excellent long cycle life along with 94.3% specific capacitance retained after 3000 cycles. These fascinating performances can be attributed to the high capacitance and the positive synergistic effects of the two electrodes. The impressive results presented here may pave the way for promising applications in high energy density storage systems. 相似文献
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双电层电容器中单/双面涂覆电极的电化学性能比较 总被引:1,自引:1,他引:0
以KOH为活化剂,采用微波加热石油焦一步法制备了微孔活性炭。采用循环伏安和恒流放电法研究了双电层电容器中单面和双面涂覆的活性炭电极电化学性能。活性炭的亚甲基蓝吸附值为247.8mg·g–1,N2吸/脱附结果表明,活性炭比表面积为1037m2·g–1,微孔孔容为0.54m3·g–1。结果表明,1000次循环后,双面涂覆电极的比容、比容保持率和两电极电容器的能量密度保持率分别为227.3F·g–1、96.6%和97.4%均高于单面涂覆电极;而双面涂覆电极的内阻仅为0.42Ω,小于单面涂覆电极的内阻。 相似文献
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Novel Core–Shell FeOF/Ni(OH)2 Hierarchical Nanostructure for All‐Solid‐State Flexible Supercapacitors with Enhanced Performance
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Mengqiao Wang Zhaoqiang Li Chengxiang Wang Ruizheng Zhao Caixia Li Dexiang Guo Luyuan Zhang Longwei Yin 《Advanced functional materials》2017,27(31)
Well‐controlled core–shell hierarchical nanostructures based on oxyfluoride and hydroxide are for the first time rationally designed and synthesized via a simple solvothermal and chemical precipitation route, in which FeOF nanorod acts as core and porous Ni(OH)2 nanosheets as shell. When evaluated as electrodes for supercapacitors, a high specific capacitance of 1452 F g?1 can be obtained at a current density of 1 A g?1. Even as the current density increases to 10 A g?1, the core–shell hybrid still reserves a noticeable capacitance of 1060 F g?1, showing an excellent rate capacity. Furthermore, all‐solid‐state flexible asymmetric supercapacitor based on the FeOF/Ni(OH)2 hybrid as a positive electrode and activated carbon as a negative electrode shows high power density, high energy density, and long cycling lifespan. The excellent electrochemical performance of the FeOF/Ni(OH)2 core–shell hybrid is ascribed to the unique microstructure and synergistic effects. FeOF nanorod from FeF3 by partial substitution of fluorine with oxygen behaves as a low intrinsic resistance, thus facilitating charge transfer processes. While the hierarchical Ni(OH)2 nanosheets with large surface area provide enough active sites for redox chemical reactions, leading to greatly enhanced electrochemical activity. The well‐controllable oxyfluoride/hydroxide hybrid is inspiring, opening up a new way to design new electrodes for next‐generation all‐solid‐state supercapacitors. 相似文献
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Ternary Hybrids of Amorphous Nickel Hydroxide–Carbon Nanotube‐Conducting Polymer for Supercapacitors with High Energy Density,Excellent Rate Capability,and Long Cycle Life
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Wenchao Jiang Dingshan Yu Qiang Zhang Kunli Goh Li Wei Yili Yong Rongrong Jiang Jun Wei Yuan Chen 《Advanced functional materials》2015,25(7):1063-1073
The utilization of Ni(OH)2 as a pseudocapacitive material for high performance supercapacitors is hindered by its low electrical conductivity and short cycle life. A coaxial ternary hybrid material comprising of amorphous Ni(OH)2 deposited on multiwalled carbon nanotubes wrapped with conductive polymer (poly (3,4‐ethylenedioxythiophene)‐poly(styrenesulfonate)) is demonstrated. A thin layer of disordered amorphous Ni(OH)2 is deposited by an effective “coordinating etching and precipitating” method, resulting in an ultrahigh specific capacitance of 3262 F g?1 at 5 mV s?1 and excellent rate capability (71.9% capacitance retention at 100 mV s?1). More importantly, the polymer layer prevents the degradation of the nanostructure and dissolution of Ni ion during repeated charge–discharge cycling for 30 000 cycles, a phenomenon which often plagues Ni(OH)2 nanomaterials. Using the ternary Ni(OH)2 hybrid and the reduced graphene oxide/carbon nanotube hybrid as the positive and negative electrodes, respectively, the assembled asymmetric supercapacitors exhibit high energy density of 58.5 W h kg?1 at the power density of 780 W kg?1 as well as long cycle life (86% capacitance retention after 30 000 cycles). The ternary hybrid architecture design for amorphous Ni(OH)2 can be regarded as a general approach to obtain pseudocapacitive materials for supercapacitors with both high energy density, excellent rate capability, and long cycle life. 相似文献