碳纳米管/氧化镍复合电极超大容量离子电容器

碳纳米管作为一种新型碳材料,具有质轻,高的有效比表面积和优良的导电性,是制备双电层电容器较为理想的电极材料。本文实验用硝酸回流处理碳纳米管,对其表面改性,通过sol-gel法在改性后的碳纳米管上沉积Ni(OH)2,经灼烧得到碳纳米管/氧化镍复合材料,制成电极装配成电容器单元。该电容器具有双电层电容和赝电容特性,其比电容量为160 F/g,频率响应特性较活性炭电极电容器有所提高,是一种极具发展潜力的储能器件。     

超大容量电容器

电解电容向超小型、大容量方向飞速发展。继日本成功地开发出Φ3超小型铝电解电容以来,现又成功地开发出100F级超大容量电容器。大家对传统的铝电解电容已不陌生,但对这种超大容量电容器了解甚少。它又名双电荷层电容。超大容量电容器与传统的铝电解电容在结构上有所不同,铝电解电容的电极材料为化学处理后的铝箔,而超大容量电容器电极材料为活性     

离子注入型超大容量固体离子电容器

本文提出了一种具有“混合导体电极/快离子导体(或快离子导体粉体与炭质极化电极颗粒混合体)/混合导体电极”结构的离子注入型超大容量固体离子电容器.其电容量除由界面双电层形成外,研究还发现电容量随混合导体电极用量增加线性增大.研究采用Cu~(+)离子导体为固体电解质,Cu_2Mo_6S_7.7为混合导体电极.其容量密度高达50F/Cm~3,等效串联电阻(ESR)为40Ω,漏电流为15μA,分解电位为600mV.     

20伏高电压型碳纳米管超级电容器的研制

通过催化裂解法制备了碳纳米管并进一步制备了碳纳米管膜片式电极.基于该种材料的超级电容器电极比容量达到42F/g并表现出良好的大电流放电特性.本文采用多种研究方法对基于该种材料的双电层电容器的电化学特性进行了详细的研究.本文还开发了全新的超级电容器组装工艺,采用该工艺组装的碳纳米管超级电容器工作电压可以达到20V并具有良好的容量特性和阻抗特性.     

超级电容

超级电容属于双电层电容器,它是世界上已投入量产的双电层电容器中容量最大的一种,其基本原理和其它种类的双电层电容器一样,都是利用活性炭多孔电极和电解质组成的双电层结构获得超大的容量。由于其容量很大,对外表现和电池相同,因此也有称作“电容电池”。     

碳纳米管-氢氧化镍复合电极电化学电容器

采用催化裂解法制备了碳纳米管并进一步制备了碳纳米管薄膜电极。基于该种材料的超电容器电极比容量为36 F/g。研究了在碳纳米管薄膜基体上使用电化学方法沉积氢氧化镍的新工艺,制备出碳纳米管/氢氧化镍复合电极。伏安特性曲线以及直流充放电实验证明复合电极的单电极比容量达到63 F/g,交流阻抗谱证明复合电极具有优良的阻抗特性。     

硝酸改性石墨毡制作超级电容器的复合电极

为了改善石墨毡(GF)表面的疏水性以及解决生长的活性物质易脱落的问题,研究了使用浓硝酸简单的一步法活化石墨毡并且引入含氧官能团.通过实验确定了合适的浓硝酸反应条件.经浓硝酸改性后的石墨毡的比电容可以达到272.6 mF·cm-2,而且,发现改性后的石墨毡(MGF)更有利于活性物质生长.与MGF结合后,用于超级电容器电极...     

室温熔盐在碳纳米管电化学电容器中的应用

将碳纳米管制成薄膜电极,以二(三氟甲基磺酸酰)亚胺锂(LiTFSI)-1,3-氮氧杂环戊-2-酮(OZO)室温熔盐为电解液,装配成模拟电容器。测试结果表明,比电容为20.5F/g,工作电压可达2.0V以上,循环充放电500次后容量损失小于5%。室温熔盐在碳纳米管电化学电容器中表现出良好的电化学兼容性,具有良好的热稳定性,是超级电容器非常有前景的新型电解液。     

电化学双电层电容器的研制

通过催化裂解法制备了碳纳米管并进一步制备了碳纳米管薄膜电极。基于该种材料的超电容器电极比容量达到36 F/g并表现出良好的功率特性。本文采用多种研究方法对基于该种材料的双电层电容器进行了详细的研究。     

静电纺丝PANI/CNT/PEO超级电容器电极的性能研究

采用静电纺丝制备高性能、薄膜纤维结构电极的超级电容器。制备了均匀对称的三明治式固态超级电容器,其电极为静电纺丝制备的聚苯胺、多壁碳纳米管、聚氧化乙烯薄膜结构,电解质为聚乙烯醇和硫酸。研究了静电纺丝参数对纤维直径的影响,通过改变纺丝距离和溶液流量可以获得微孔薄膜纤维电极。当纺丝距离从80 mm提高到140 mm,纤维的平均直径从3.22μm降低到1.40μm,相对应电极的比电容从70 F/g上升到95 F/g。用这种纤维结构电极制备的超级电容器表现出很好的循环稳定性,用平均纤维直径1.40μm的电极制作的超级电容器在1 000次充放电之后比电容仍能保持90%。     

超电容器活性炭电极储电影响因素的研究

用活性炭作为超电容器的电极材料,在不同条件下对超电容器进行充放电测试,考察其在不同充电条件下的容量变化。实验发现,微孔活性炭比表面积较大时有储电的优势,电容器在充电电流强度较小时有较大的容量;随着电流强度的增加,充放电容量逐渐降低。不同的充电方式对其储电容量有较大的影响,漏电流是影响双电层电容器性能的一个重要因素。     

Analysis of the dynamic behavior changes of supercapacitors during calendar life test under several voltages and temperatures conditions

Supercapacitors, also known as ultracapacitors are based on porous activated carbon electrodes and on electrostatic charge storage mechanisms. Carbon electrodes are supposed to be chemically and electrochemically inert and the electrostatic nature of the charge storage mechanism is highly reversible. These properties should assure that supercapacitors have an infinite shelf life. But in practice, supercapacitor cells exhibit performances fading when they are used for months. The purpose of this paper is to evaluate the performances fading of supercapacitors during calendar life test which correspond to lower current solicitations than power cycling test. In case of hybrid electric vehicle, which is a key application of ultracapacitors, this ageing test is useful because long rest periods represent a significant time of the vehicle real use. The degradation method of calendar life tests consists in maintaining the cells at high voltage and temperature. A periodic characterization based on impedance spectroscopy is done in order to quantify impedance changes. The obtained results confirm that impedance real part is increasing and the capacitance is decreasing.     

Enhancing the Capacitive Storage Performance of Carbon Fiber Textile by Surface and Structural Modulation for Advanced Flexible Asymmetric Supercapacitors

The exploration of high‐energy anodes with good mechanical properties is highly attractive for flexible asymmetric supercapacitors (ASCs) but challenging. Owing to the excellent conductivity and superior mechanical flexibility, carbon fiber textile (CFT) holds great promise as a substrate/current‐collector for fabricating flexible electrodes. Yet, it is rarely used as a flexible active electrode in terms of its low electrochemical reactivity and small accessible area. In this work, an effective surface and structural modulation strategy is developed to directly tune CFT into a highly active anode for flexible ASCs by creating hierarchical pores and numerous pseudocapacitive oxygenic groups. Arising from large surface and increased active sites, the as‐prepared activated porous CFT (APCFT) electrode not only achieves a large capacitance (1.2 F cm^?2 at 4 mA cm^?2) and fast kinetics but also shows satisfying cycling durability (no capacitance decay after 25 000 cycles). More importantly, an advanced flexible ASC device with an impressive energy density of 4.70 mWh cm^?3 is successfully assembled by employing this APCFT as an anode, outperforming most recently reported ASC devices. This dual modification strategy may throw light on the rational design of new generation advanced carbon electrodes for high‐performance flexible supercapacitors.     

Detonation Nanodiamond and Onion‐Like‐Carbon‐Embedded Polyaniline for Supercapacitors

The detonation nanodiamond is a versatile low‐cost nanomaterial with tunable properties and surface chemistry. In this work, it is shown how the application of nanodiamond (ND) can greatly increase the performance of electrochemically active polymers, such as polyaniline (PANI). Symmetric supercapacitors containing PANI‐ND nanocomposite electrodes with 3–28 wt% ND show dramatically improved cycle stability and higher capacitance retention at fast sweep rate than pure PANI electrodes. Contrary to other PANI‐carbon nanocomposites, specific capacitance of the selected PANI electrodes with embedded ND increases after 10 000 galvanostatic cycles and reaches 640 F g^?1, when measured in a symmetric two‐electrode configuration with 1 M H₂SO₄ electrolyte. The demonstrated specific capacitance is 3–4 times higher than that of the activated carbons and more than 15 times higher than that of ND and onion‐like carbon (OLC).     

Fabrication of Hybrid Supercapacitor by MoCl5 Precursor-Assisted Carbonization with Ultrafast Laser for Improved Capacitance Performance

Hybrid supercapacitors use electric double-layer capacitance and Faradaic pseudocapacitance as energy storage mechanisms. This type of supercapacitor is becoming a prime candidate for next-generation energy storage devices, with advantages in terms of energy density, specific capacitance, and life cycle. However, reducing the electrode area and increasing the specific capacitance of hybrid supercapacitors remain challenging. In this study, a MoCl₅ Precursor-assisted Ultrafast Laser Carbonization (MPAULC) method to fabricate symmetric hybrid supercapacitors with improved capacitance and reduced size is proposed. The method uses an ultrafast laser to induce the formation of carbon/MoO₃ composite with the assistance of the MoCl5 precursor. This ultrafast laser carbonization method exhibited high processing precision. The role of the precursor in laser processing is studied using time-resolved imaging and temperature calculations. The specific area capacitance of the C/MoO₃ hybrid supercapacitor is 11.85 mF cm⁻², 9.2 times higher than that of the laser-induced carbon supercapacitor without precursor. The MPAULC method provides a reliable pathway for fabricating miniaturized hybrid supercapacitors with carbon/metal oxide composite electrodes on polymer substrates.     

Sputtered Titanium Carbide Thick Film for High Areal Energy on Chip Carbon‐Based Micro‐Supercapacitors

The areal energy density of on‐chip micro‐supercapacitors should be improved in order to obtain autonomous smart miniaturized sensors. To reach this goal, high surface capacitance electrode (>100 mF cm^?2) has to be produced while keeping low the footprint area. For carbide‐derived carbon (CDC) micro‐supercapacitors, the properties of the metal carbide precursor have to be fine‐tuned to fabricate thick electrodes. The ad‐atoms diffusion process and atomic peening effect occurring during the titanium carbide sputtering process are shown to be the key parameters to produce low stress, highly conductive, and thick TiC films. The sputtered TiC at 10^?3 mbar exhibits a high stress level, limiting the thickness of the TiC‐CDC electrode to 1.5 µm with an areal capacitance that is less than 55 mF cm^?2 in aqueous electrolyte. The pressure increase up to 10^?2 mbar induces a clear reduction of the stress level while the layer thickness increases without any degradation of the TiC electronic conductivity. The volumetric capacitance of the TiC‐CDC electrodes is equal to 350 F cm^?3 regardless of the level of pressure. High values of areal capacitance (>100 mF cm^?2) are achieved, whereas the TiC layer is relatively thick, which paves the way toward high‐performance micro‐supercapacitors.     

High‐Performance Supercapacitor Applications of NiO‐Nanoparticle‐Decorated Millimeter‐Long Vertically Aligned Carbon Nanotube Arrays via an Effective Supercritical CO2‐Assisted Method

Nickel oxide (NiO) nanoparticles are distributed uniformly in the vertically aligned carbon nanotube arrays (VACNTs) with millimeter thickness by an effective supercritical carbon dioxide‐assisted method. The as‐prepared VACNT/NiO hybrid structures are used as electrodes without binders and conducting additives for supercapacitor applications. Due to the synergetic effects of NiO and VACNTs with nanoporous structures and parallel 1D conductive paths for electrons, the supercapacitors exhibit a high capacitance of 1088.44 F g^?1. Furthermore, an asymmetric supercapacitor is assembled using the as‐synthesized VACNTs/NiO hybrids as the positive electrode and the VACNTs as the negative electrode. Remarkably, the energy density of the asymmetric supercapacitor is as high as 90.9 Wh kg^?1 at 3.2 kW kg^?1 and the maximum power density reaches 25.6 kW kg^?1 at 24.9 Wh kg^?1, which are superior to those of the NiO or VACNTs‐based asymmetric supercapacitors. More importantly, the asymmetric supercapacitors exhibit capacitance retention of 87.1% after 2000 cycles at 5 A g^?1. The work provides a novel approach in decorating highly dense and long VACNTs with active materials, which are promising electrodes for supercapacitors with ultrahigh power density and energy density.     

Stretchable Supercapacitor with Adjustable Volumetric Capacitance Based on 3D Interdigital Electrodes

Reduced graphene oxide (rGO)‐based materials have shown good performance as electrodes in flexible energy storage devices owing to their physical properties, high specific surface area, and excellent electrical conductivity. Here, a novel road is reported for fabricating high‐performance supercapacitors based on 3D rGO electrodes and solid electrolyte multilayers via pressure spray printing and machine coating. These supercapacitors demonstrate high and adjustable volumetric capacitance, excellent flexibility, and stretchability. The results show that this commercial strategy has its essential merits such as low‐cost, inexpensive, and simple fabrication for large area production. These properties are in the favor of fabricating high‐performance supercapacitor to meet the practical energy demands in devices, especially flexible electronic devices. Furthermore, this novel 3D interdigital electrode concept can be widely applied to other energy devices for enhancing performances and to other micro devices for reducing cost.     

碳纳米管–聚吡咯复合材料在超电容器中的应用

在碳纳米管(CNT)基体上用化学聚合或电化学聚合方法沉积聚吡咯(PPy)制得复合材料。再以此类复合材料为活性物质制作电极,组装成原型超电容器。并对其进行了循环伏安、恒电流充放电等电化学测试。用此类复合材料制成的原型超电容器的比容量(23.6 F/g)与纯碳纳米管(2.3 F/g)或纯聚吡咯(3.9 F/g)制成的原型电容器比较,发现复合电极电容器比容量的提高不是简单的加和效应,而是协同效应所致。