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以核桃壳为原料,采用KOH活化法制备活性炭,并将其用作超级电容器电极材料。利用N2吸附和扫描电镜(SEM)表征活性炭的孔结构及表面形貌,系统研究碱炭比(KOH与核桃壳炭化料的质量比)对活性炭孔结构的影响,并采用恒流充放电及循环伏安等测定核桃壳活性炭电极材料在3mol/L KOH电解液中的电化学性能。结果表明,随着碱炭比的增大,活性炭的比表面积、总孔容及中孔比例先逐渐增大后稍有减小。当活化温度为800℃,活化时间为1h,碱炭比为4时,可制备出比表面积为2404m2/g,总孔容为1.344cm3/g,中孔比例为28.6%,孔径分布在0.7~3.0nm之间的高比表面积活性炭。该活性炭用作超级电容器电极材料具有良好的大电流放电特性和优异的循环性能,电流密度由50mA/g提高到5000mA/g时,其比电容由340F/g降低到288F/g,经1000次循环后,比电容保持率为93.4%。 相似文献
14.
MXene Yarn Supercapacitors: High‐Performance Biscrolled MXene/Carbon Nanotube Yarn Supercapacitors (Small 37/2018)
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15.
Compared with other flexible energy‐storage devices, the design and construction of the compressible energy‐storage devices face more difficulty because they must accommodate large strain and shape deformations. In the present work, CoNi2S4 nanoparticles/3D porous carbon nanotube (CNT) sponge cathode with highly compressible property and excellent capacitance is prepared by electrodepositing CoNi2S4 on CNT sponge, in which CoNi2S4 nanoparticles with size among 10–15 nm are uniformly anchored on CNT, causing the cathode to show a high compression property and gives high specific capacitance of 1530 F g−1. Meanwhile, Fe2O3/CNT sponge anode with specific capacitance of 460 F g−1 in a prolonged voltage window is also prepared by electrodepositing Fe2O3 nanosheets on CNT sponge. An asymmetric supercapacitor (CoNi2S4/CNT//Fe2O3/CNT) is assembled by using CoNi2S4/CNT sponge as positive electrode and Fe2O3/CNT sponge as negative electrode in 2 m KOH solution. It exhibits excellent energy density of up to 50 Wh kg−1 at a power density of 847 W kg−1 and excellent cycling stability at high compression. Even at a strain of 85%, about 75% of the initial capacitance is retained after 10 000 consecutive cycles. The CoNi2S4/CNT//Fe2O3/CNT device is a promising candidate for flexible energy devices due to its excellent compressibility and high energy density. 相似文献
16.
Green Synthesis of Hierarchically Porous Carbon Nanotubes as Advanced Materials for High‐Efficient Energy Storage
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Jian‐Gan Wang Hongzhen Liu Xingyuan Zhang Xu Li Xingrui Liu Feiyu Kang 《Small (Weinheim an der Bergstrasse, Germany)》2018,14(13)
Hierarchically porous carbon nanomaterials with well‐defined architecture can afford a promising platform for effectively addressing energy and environmental concerns. Herein, a totally green and straightforward synthesis strategy for the fabrication of hierarchically porous carbon nanotubes (HPCNTs) by a simple carbonization treatment without any assistance of soft/hard templates and activation procedures is demonstrated. A high specific surface area of 1419 m2 g?1 and hierarchical micro‐/meso‐/macroporosity can be achieved for the HPCNTs. The unique porous architecture enables the HPCNTs serving as excellent electrode/host materials for high‐performance supercapacitors and Li–sulfur batteries. The design strategy may pave a new avenue for the rational synthesis of hierarchically porous carbon nanostructures for high‐efficient energy storage applications. 相似文献
17.
Energy Storage: Confined Assembly of Hollow Carbon Spheres in Carbonaceous Nanotube: A Spheres‐in‐Tube Carbon Nanostructure with Hierarchical Porosity for High‐Performance Supercapacitor (Small 19/2018)
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18.
纳米MnO2超级电容器电解液性能研究 总被引:4,自引:0,他引:4
利用溶胶凝胶法制备纳米MnO2,由该样品制成的电极在(NH4)2SO4电解液中表现出良好的电容性能。考虑到(NH4)2SO4溶液对集流体泡沫镍的腐蚀,开展了向(NH4)2SO4溶液中加入添加剂(Na2SO4、K2SO4、MgSO4)以减缓(NH4)2SO4对泡沫镍腐蚀的研究,研究了添加剂的添加量和电解液的摩尔浓度对MnO2电极的电化学性能和对泡沫镍的腐蚀程度的影响。发现采用MgSO4的摩尔百分含量为50%、电解液的摩尔浓度[以(NH4)2SO4 添加剂的摩尔浓度计]为0.5 mol·L-1的电解液基本上不降低MnO电极的电化学性能,却大幅降低对泡沫镍的腐蚀程度。 相似文献
19.
Xiaojun Du Wenge Wu Chunhua An Yunping Cheng Xinyu Zhang Youyi Sun Yaqing Liu 《国际能源研究杂志》2016,40(12):1731-1738
Three‐dimensional (3D) graphene network deposition on Ni foam without any conductive agents and polymer binders was successfully synthesized by radio frequency magnetron sputtering at low temperature. The direct and close contact between graphene and Ni foam is beneficial to the enhanced conductivity of the electrode, as well as the improvement of ion diffusion/transport into the electrode. As a result, the 3D graphene network deposition on Ni foam electrode delivered a high specific capacitance of 122.0 F g−1 at 1.0 A g−1 and excellent cycle stability with capacitance retention of 99.0% after 1000 charge–discharge cycles. The work shows a new way to facile synthesis of 3D graphene network for various applications in the future. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
20.
Mingyu You Wenjing Zhang Xuehua Yan Hui Jiang Jieyu Miao Yanli Li Wending Zhou Yihan Zhu Xiaonong Cheng 《Ceramics International》2021,47(3):3337-3345
As an emerging energy storage device, supercapacitor is widely investigated owing to its excellent capability, quick charge-discharge and tremendous cycle life. The operation potential window, energy density and mass loading of supercapacitor must be taken into deep consideration for its practical application. In this work, an outstanding electrode based on CFF@V2O5 nanosheets was prepared. Then a free-standing asymmetric supercapacitor with CFF@V2O5 composite as positive electrode and CFF@AC as negative electrode was assembled. Owing to the functional groups produced on CFF after the activation, V2O5 nanosheets was immobilized. The composite exhibits remarkable specific capabilities of 1465 mF cm?2 (492 F g?1). The energy density of the assembled free-standing asymmetric supercapacitor achieves 0.928 mWh cm?3 when the power density is 17.5 mW cm?3. After 6000 charging-discharging cycles as under normal, bended and anti-bended conditions for respective 2000 cycles, the device retains 89.7% of the initial capacitance, exhibiting fascinating cycle stabilization. Finally, two devices linked series can lighten a LED of 1.8 V for 2 min after charging for 2.5 min, which is inspiring for the practical application and production of self-supporting asymmetric supercapacitors. 相似文献