聚噻吩/活性炭复合材料作为超级电容器电极材料的电性能

采用原位聚合的方法在活性炭表面引发噻吩聚合,制备不同配比的聚噻吩/活性炭复合材料作为超级电容器电极材料,并研究了不同配比对材料电性能及结构的影响.采用傅里叶红外光谱及场发射扫描电镜研究了材料的化学结构及表面形态.采用循环伏安,恒流充放电等方法评价了材料电性能.结果表明,当活性炭与噻吩的摩尔比为10:1时,复合材料呈蓬松...     

Controlled Incorporation of Ni(OH)2 Nanoplates Into Flowerlike MoS2 Nanosheets for Flexible All‐Solid‐State Supercapacitors

In this work, self‐supporting three‐dimensional hierarchical nanostructured MoS₂@Ni(OH)₂ nanocomposites are synthesized via a facile single‐mode microwave hydrothermal technique. The fabricated MoS₂@Ni(OH)₂ nanocomposites for supercapacitors in aqueous electrolyte exhibit higher specific capacitance and better cyclic stability than those of MoS₂ and Ni(OH)₂ due to the pronounced synergistic effect between MoS₂ and Ni(OH)₂. Further, the flexible all‐solid‐state supercapcitor is readily constructed by composing the PVA/KOH gel electrolyte in between two MoS₂@Ni(OH)₂ electrodes on the flexible PET substrates. The resulting supercapacitors can operate at high rate up to 1000 V/s, have excellent long‐life cycling stability, retaining 94.2% of the initial capacitance after 9000 cycles, and mechanical flexibility during extreme bending, respectively. Thereby, the MoS₂@Ni(OH)₂ nanocomposites are a promising electrode materials for flexible long‐life cycling all‐solid‐sate supercapacitors.     

三维结构钴镍基双金属硫化物对超级电容器的影响[*]

采用水热法成功制备出三维结构NiCo2O4和NiCo2S4纳米材料,将其应用于超级电容器电极材料。通过XRD对材料的物相组成进行分析,用SEM和TEM对材料的表面形貌和结构进行观察分析,三维结构有利于电解液对电极材料浸润,从而极大地提升材料电化学性能。通过恒电流充放电、交流阻抗和长循环等电化学实验测试对比分析发现,双金属硫化物相比于氧化物具有更加优异的电化学性能,主要是由于硫元素具有更小的电负性且电化学反应活性较高。NiCo2S4电极材料恒电流充放电及长循环测试容量保持率分别为79.69%和76.66% ,与NiCo2O4材料的68.1%和59.64%相比展现出优异的稳定性能。     

超电容器复合活性炭电极的制备及性能研究

用高比表面积活性炭作为原料,酚醛树脂为粘结剂,在120℃高温下粘结成型制备系列超电容器用固体活性炭电极,改变酚醛树脂添加量考察不同炭化温度对复合活性炭电极炭化收率的影响。实验发现,随着炭化温度的提高,复合活性炭电极的炭化收率呈逐渐降低的趋势,炭化温度高于800℃时复合活性炭电极比电容量下降。酚醛树脂掺杂量多时收率降低。另外在酚醛树脂中加入固化剂可提高其炭化收率。不同组成的复合活性炭电极中,微孔活性炭含量大,则比电容量高。     

Electrochemically Tuned Properties for Electrolyte‐Free Carbon Nanotube Sheets

Injecting high electronic charge densities can profoundly change the optical, electrical, and magnetic properties of materials. Such charge injection in bulk materials has traditionally involved either dopant intercalation or the maintained use of a contacting electrolyte. Tunable electrochemical charge injection and charge retention, in which neither volumetric intercalation of ions nor maintained electrolyte contact is needed, are demonstrated for carbon nanotube sheets in the absence of an applied field. The tunability of electrical conductivity and electron field emission in the subsequent material is presented. Application of this material to supercapacitors may extend their charge‐storage times because they can retain charge after the removal of the electrolyte.     

微波辐射制备两种超级电容器用活性炭的研究

以微波为热源,无烟煤、炭化椰壳为原料,KOH为活化剂制备了两种超级电容器用活性炭电极材料。对比考察了两种活性炭在相同实验条件下的比电容、冲放电性能、循环稳定性、内阻;讨论了微波辐射时间对两种活性炭比电容量的影响。研究结果表明：以无烟煤、炭化椰壳为原料制备的活性炭单电极比电容分别达301F／g、266F／g,且两种活性炭均具有良好的冲放电特性;炭化椰壳制备的活性炭比无烟煤制备的活性炭循环稳定性更好,内阻更低。     

Motion control of electric vehicles and prospects of supercapacitors

Novel motion control techniques for electric vehicles (EVs) on the basis of the quick torque generation in these vehicles have been developed at the Hori Laboratory. Because EVs are powered by electric motors, they have three major advantages: (i) motor torque generation is quick and accurate, (ii) a motor can be attached to each wheel, and (iii) motor torque can be estimated precisely. These advantages enable us to (i) easily realize high-performance antilock braking systems and traction control systems with minor feedback control of each wheel, (ii) control chassis motion, for example, direct yaw control, and (iii) estimate road surface condition. We have developed test vehicles and confirmed the effectiveness of the proposed methods. Recently, we have manufactured small EVs that are powered only by supercapacitors. Supercapacitors have long operating life, large current density, and are environmental friendly. Furthermore, their energy level can be estimated from their terminal voltage. Because EVs powered by supercapacitors can run for more than 20 min by charging only for 30 s, recharging EVs will not be a major problem. In the future, EVs will be recharged via contactless power transfer. Copyright © 2009 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.