氮化钒/多孔蚕茧碳复合电极材料的制备及超电容特性研究

本论文采用环境友好的蚕茧,结合简单的水热法,制备了性能优异的片层状氮化钒/多孔蚕茧碳复合电极材料。该材料具有良好的超电容特性,在硫酸水系电解液中,在5 mV·s~(-1)扫描速率下,可以达到269 F/g,同时具有较好的倍率特性,在200 mV·s~(-1)扫描速率下,比电容仍可以达到161 F/g。同时,该材料具有良好的循环特性,4000次50 mV/s的循环比电容保持率接近99%。     

聚苯胺/壳聚糖超级电容器电极复合材料的制备及表征

采用冷冻干燥后管式炉碳化制备壳聚糖电极材料,经KOH活化法活化后通过氧化还原聚合法制备聚苯胺(PANI)/壳聚糖电极材料,运用循环伏安、交流阻抗、充放电等测试聚苯胺/壳聚糖电极的电化学性能。结果表明,聚苯胺/壳聚糖电极材料表现出良好的电容性能和稳定的电化学性能,比电容129.6 F/g,循环充放电500次,比电容保持率90.8%。     

聚苯胺/壳聚糖超级电容器电极复合材料的制备及表征

采用冷冻干燥后管式炉碳化制备壳聚糖电极材料,经KOH活化法活化后通过氧化还原聚合法制备聚苯胺(PANI)/壳聚糖电极材料,运用循环伏安、交流阻抗、充放电等测试聚苯胺/壳聚糖电极的电化学性能。结果表明,聚苯胺/壳聚糖电极材料表现出良好的电容性能和稳定的电化学性能,比电容129.6 F/g,循环充放电500次,比电容保持率90.8%。     

氧化石墨烯/聚苯胺材料的制备及其超电容性能研究

通过乳液聚合制备具有类似金属导电性和超电容功能的氧化石墨烯/聚苯胺(GO-PANI)复合材料,聚合在组成为水,乙醇,二甲苯和十二烷基苯磺酸(DBSA)的乳液中进行。采用红外光谱对材料进行了表征,采用循环伏安法、交流阻抗和恒电流充放电进行了材料电化学性能的测试。结果表明氧化石墨烯/聚苯胺呈现高的超电容性能。在0.5 A/g电流密度下,摩尔比为3∶7材料的比电容高达444 F/g,远远超过了氧化石墨烯的比电容(134 F/g)。在50 mV/s下循环1000次,GO-PANI(3/7)仍呈现出高的比电容,达到412 F/g,仅减少7.2%。相对于纯聚苯胺比电容下降41.7%,复合材料GO-PANI具有优良的稳定性,显著提高复合材料容量保持率和循环寿命。     

CB/PANI/MnO_2复合材料的制备及电化学性能的研究

通过原位聚合法合成CB/PANI/MnO_2复合电极材料,对电极材料进行循环伏安、交流阻抗和恒电流充放电等电化学性能测试;通过循环伏安法(CV)测试,得出高锰酸钾添加量为0.3 g时,CB/PANI/MnO_2复合电极材料的电化学性能效果最好,在5 mV/s的扫描速度下其比容量可达到190 F/g;高锰酸钾添加量为0.3 g时,CB/PANI/MnO_2复合电极材料在0.5 A/g的电流密度下,电极材料的质量比电容高达354 F/g。     

CB/PANI/MnO_2复合材料的制备及电化学性能的研究

通过原位聚合法合成CB/PANI/MnO_2复合电极材料,对电极材料进行循环伏安、交流阻抗和恒电流充放电等电化学性能测试;通过循环伏安法(CV)测试,得出高锰酸钾添加量为0.3 g时,CB/PANI/MnO_2复合电极材料的电化学性能效果最好,在5 mV/s的扫描速度下其比容量可达到190 F/g;高锰酸钾添加量为0.3 g时,CB/PANI/MnO_2复合电极材料在0.5 A/g的电流密度下,电极材料的质量比电容高达354 F/g。     

微撞击流反应器制备镍钴复合氢氧化物超级电容器材料及其性能研究

镍基复合超级电容器电极材料如镍钴复合氢氧化物,由于其比电容大、循环性能好等优点受到了电化学界的广泛关注。相比于纯Ni(OH)₂,镍钴复合氢氧化物材料由于过渡金属元素之间的协同作用,其电化学性能一般会更佳。但是镍钴复合氢氧化物材料的性能与其颗粒内部的组分分布均匀性有很大关联,而组分分布又依赖于沉淀反应时反应器内的微观混合均匀程度。将微观混合性能优良的微撞击流反应器（MISR）应用于镍钴复合氢氧化物材料的共沉淀制备,结果表明MISR能够显著改善镍钴复合氢氧化物材料的颗粒粒径、尺寸分布、团聚程度以及电化学性能：三电极体系测试下,所制备材料的初始比电容为1548.0 F/g,1000圈充放电循环后电容保持率为106.0%;二电极体系测试下,器件的初始比电容为30.6 F/g,1000圈循环后电容保持率为75.6%。     

微撞击流反应器制备镍钴复合氢氧化物超级电容器材料及其性能研究

镍基复合超级电容器电极材料如镍钴复合氢氧化物,由于其比电容大、循环性能好等优点受到了电化学界的广泛关注。相比于纯Ni(OH)₂,镍钴复合氢氧化物材料由于过渡金属元素之间的协同作用,其电化学性能一般会更佳。但是镍钴复合氢氧化物材料的性能与其颗粒内部的组分分布均匀性有很大关联,而组分分布又依赖于沉淀反应时反应器内的微观混合均匀程度。将微观混合性能优良的微撞击流反应器（MISR）应用于镍钴复合氢氧化物材料的共沉淀制备,结果表明MISR能够显著改善镍钴复合氢氧化物材料的颗粒粒径、尺寸分布、团聚程度以及电化学性能：三电极体系测试下,所制备材料的初始比电容为1548.0 F/g,1000圈充放电循环后电容保持率为106.0%;二电极体系测试下,器件的初始比电容为30.6 F/g,1000圈循环后电容保持率为75.6%。     

自支撑石墨烯/二氧化锰/泡沫镍复合材料的电化学性能

以三维泡沫镍(NF)为模板,在不添加模板剂的条件下,通过电沉积法沉积石墨烯(G),再采用水热合成制备纳米片二氧化锰(Mn O_2),得到自支撑电极复合材料G/Mn O_2/NF,改善其作为电极材料的电化学性能。用X射线衍射(XRD)、拉曼光谱(Raman)和扫描电子显微镜(SEM)对复合材料的微观结构和表面形貌进行分析,通过循环伏安(CV)、恒电流充放电(GCD)、交流阻抗(EIS)测试了电极复合材料的电化学性能。结果表明:在电流密度为1 A/g的条件下,复合电极材料的比电容达到722 F/g,经过1 000次循环后比电容保持率为97%。     

木质素纳米颗粒/天然纤维基活性碳纤维材料的制备及其电化学性能

以木质素纳米颗粒（LNPs）负载的天然纤维复合材料为研究对象,利用KOH活化的方法对其进行处理制备生物质基复合多孔活性碳纤维电极材料。随后在三电极体系中对合成的复合多孔活性碳纤维电极材料进行了电化学性能测试。研究表明,在0.5A/g的电流密度下,KOH活化的复合碳纤维电极材料的比电容为351.13F/g,远高于相同条件下未活化的复合碳纤维电极材料的比电容（7.88F/g）和未负载LNPs的天然纤维基活性碳纤维材料（306.50F/g）。而且在活化过程中,负载在纤维表面的LNPs会形成多孔的活性碳层结构,这会进一步提高复合活性碳纤维材料的循环稳定性,同时LNPs中丰富的羟基赋予复合材料额外的赝电容。在10A/g的电流密度下经过10000次循环后,复合活性碳纤维电极材料的电容保持率仍然为95%,高于未负载LNPs的活性碳纤维电极材料的电容保持率87%。结果表明,木质素纳米颗粒/天然纤维基活性碳纤维材料是一种理想的电极材料,本研究也为LNPs在生物质碳纤维作为储能电极材料的高值化应用提供了一条新途径。     

Microwave-assisted efficient exfoliation of MXene and its composite for high-performance supercapacitors

MXene, as a promising electrode material, exhibits outstanding performance in supercapacitors because of its excellent chemical and physical properties. However, the conventional inefficient exfoliation methods and the blocked ion transmission channels caused by self-weight accumulation of MXene nanoflakes all severely limit its development. Here, this work reports an efficient microwave exfoliation method that requires only 90s to exfoliate multilayered MXene into few-layer MXene (2–3 nm) with large-size (4～6 μm). Additionally, to enhance its capacitance and cycling stability, the exfoliated MXene was composited with graphene quantum dots, which shows a larger specific surface area, and importantly performs ultrahigh capacitance (343 F/g at a current density of 1 A/g) and excellent capacitance retention (100% after 10,000 cycles at a current density of 5 A/g). When using composite material as an anode, the assembled supercapacitor exhibits an excellent energy density of 35 Wh/kg at a power density of 384 W/kg with 107% capacitance retention after 10,000 cycles. Not only does this work provide an efficient approach to exfoliate MXene, but it also prepares a highly promising material for energy storage materials.     

Electrochemical characterization of carbon nanotubes as electrode in electrochemical double-layer capacitors

Carbon nanotubes uniformly 50 nm in diameter were directly grown on graphite foil. Cyclic voltammetry (CV) shows that the carbon nanotube/graphite foil electrode has a high specific capacitance (115.7 F/g at a scan rate of 100 mV/s) and exhibits typical double-layer behavior. A rectangular-shaped CV curve persists even at a scan rate of 100 mV/s in 1.0 M H₂SO₄ aqueous solution, which suggests that the carbon nanotube electrode could be an excellent candidate as the electrode in electrochemical double-layer capacitors. In addition, the influence of the potential scan rate, aging, and the electrolyte solution on the specific capacitance of nanotube electrodes was also studied.     

Enhanced performance by polyaniline/tailored carbon nanotubes composite as supercapacitor electrode material

Polyaniline/tailored carbon nanotubes composite (PANI/TCN) synthesized via situ polymerization of aniline monomer in the presence of tailored carbon nanotubes (TCN) is reported as electrode material for supercapacitors. The morphology, structure, and thermostability of the composite were characterized by scanning electron microscope, Fourier transform infrared, and thermogravimetric analysis. The electrochemical property of the resulting material was systematically studied using cyclic voltammetry and galvanostatic charge–discharge. The results show that the short rod‐like PANI dispersed well in the TCN with three‐dimensional network structure. The as‐prepared composite shows high specific capacitance and good cycling stability. A specific capacitance of 373.5 F g^?1 at a current density of 0.5 A g^?1 was achieved, which is much higher than that of pure PANI (324 F g^?1). Meanwhile, the composite retains 61.7% capacity after 1000 cycles at a scan rate of 50 mV s^?1. The enhanced specific capacitance and capacity retention indicates the potential of composite as a promising supercapacitor electrode material. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2014 , 131, 39971.     

Nanostructured V2O5 and its nanohybrid with MXene as an efficient electrode material for electrochemical capacitor applications

Vanadium pentoxide (V₂O₅) is an excellent electrode material for electrochemical capacitor (ECCs) applications, but its lower electrical conductivity is the primary obstacle that restricts its practical applications. This obstacle can be eliminated by forming its nanohybrid (NCs) with a highly capacitive and conductive matrix such as MXene. MXene is a new two-dimensional (2D) material with good electronic conductivity and a larger specific surface area, making it a very suitable substrate for composite formation. Unfortunately, the two-dimensional MXene sheets stacked quickly, limiting their specific surface area and charge/mass transport properties. Here we used the hydrothermal approach to fabricate V₂O₅ nanowires (NWs) and form their nanohybrid with MXene via the ultrasound route. To assess electrochemical suitability, the fabricated samples were loaded onto a carbon cloth (CC) and used as a working electrode in the half-cell configuration. The nanohybrid (V₂O₅/MXene) sample showed a good specific capacity (C_sp) of 768 F/g (at 1 A/g) because of its greater surface area, hybrid composition, excellent electrical conductivity, and passive nanostructure. It also showed superior cyclic, electrochemical and mechanical capability and maintained a specific capacity of 93.3%, even after completion of 6000 GCD tests. In addition, the nanohybrid sample electrode also exhibits superb rate performance and lost only 14.4% of its initial specific capacity on increasing the applied current density from 1 to 5 A/g. There is no doubt that V₂O₅ NWs inter-stack between MXene nanosheets to develop effective interface interaction and suppress their stacking.     

橡胶木纤维素纳米纤丝/二氧化锰/碳纳米管柔性电极材料的制备及表征

以橡胶木为原料,通过化学处理得到橡胶木纯化纤维素(PCF),在此基础上通过高速剪切结合超声波处理制备得到纤维素纳米纤丝(CNF)。通过单相合成法制备二氧化锰(MnO₂)纳米片。以CNF为结构支撑体,MnO₂纳米片和碳纳米管(CNTs)作为活性电极物质,通过真空抽滤的方式制备CNF/MnO₂/CNTs柔性电极材料。采用多种手段对CNF、MnO₂以及电极材料的结构性能进行表征,并测试了电极材料的电化学性能。结构性能表征结果表明：CNF的直径为3~10 nm,具有大的长径比,是很好的结构支撑体,CNF为纤维素Ⅰ型结构;MnO₂纳米片为片层花瓣状结构,晶型为δ型。电化学性能测试结果表明：在扫描速率为50 mV/s时电极材料的比电容值为78.45 F/g,在电流密度为0.1 A/g时的电极材料比电容值为97.02 F/g,在低频区时,交流阻抗(EIS)曲线的直线部分斜率较大,表明电极材料具有良好的电容特性,在200次充放电循环测试过程中,电极材料的电容保留率始终维持在99%左右,表明该电极材料具有良好的电化学性能并且具有一定的柔性变形能力,可用作超级电容器的电极材料。     

Facile synthesis of graphene/polyaniline composite hydrogel for high-performance supercapacitor

The graphene/polyaniline (PANI) composite hydrogel was successfully prepared by a one-step hydrothermal method. The morphology and structure of the sample were characterized by digital camera, scanning electron microscopy, and Fourier transform infrared spectroscopy spectra. By combining the advantages of high conductivity of graphene and high pseudocapacitance of PANI, the composite hydrogel was taken as supercapacitor electrode material. Cyclic voltammetry and galvanostatic charge/discharge experimental results show that the composite has excellent electrochemical performance. The specific capacitance value is 258.5 F g^?1 at a scan rate of 2 mV s^?1 and the specific capacitance value is up to 307 F g^?1 at a current density of 0.2 A g^?1. The specific capacitance value can still maintain 90 % of the initial value after repeating the galvanostatic charge–discharge for 1000 cycles at a current density of 1.0 A g^?1 showing good cycle stability.     

Polyaniline nanowire array encapsulated in titania nanotubes as a superior electrode for supercapacitors

Conducting polymer with 1D nanostructure exhibits excellent electrochemical performances but a poor cyclability that limits its use in supercapacitors. In this work, a novel composite electrode made of polyaniline nanowire-titania nanotube array was synthesized via a simple and inexpensive electrochemical route by electropolymerizing aniline onto an anodized titania nanotube array. The specific capacitance was as high as 732 F g(-1) at 1 A g(-1), which remained at 543 F g(-1) when the current density was increased by 20 times. 74% of the maximum energy density (36.6 Wh kg(-1)) was maintained even at a high power density of 6000 W kg(-1). An excellent long cycle life of the electrode was observed with a retention of ～86% of the initial specific capacitance after 2000 cycles. The good electrochemical performance was attributed to the unique microstructure of the electrode with disordered PANI nanowire arrays encapsulated inside the TiO(2) nanotubes, providing high surface area, fast diffusion path for ions and long-term cycle stability. Such a nanocomposite electrode is attractive for supercapacitor applications.     

高导电三明治状MnO2/CNTs/MnO2介孔材料的制备及其赝电容性能

MnO₂具有低成本、无毒性、高天然丰度和优异的理论比电容等优点,被认为是一种极具前景的超级电容器(SC)电极材料。赝电容电极材料MnO₂仍然存在导电性差以及充放电过程中易剥落的问题。本文利用恒电流沉积的方法在硝酸预氧化处理的碳纸表面制备了一种MnO₂/CNTs/MnO₂复合电极材料。X射线衍射(XRD)、扫描电子显微镜(SEM)和氮吸附测试证明,所制备的复合材料具有一种三明治状的夹层结构,同时富含5 nm左右的介孔,介孔结构能够保证电解液离子的高效传输。采用三维立体的碳纸能够为MnO₂提供丰富的附着位点,而电沉积法合成的α-MnO₂生长在有效的导电位点上,具有蓬松多孔的形貌,在MnO₂发生膨胀/收缩过程中,这种海绵状形貌可以有效降低材料受到的膨胀应力。中间层碳纳米管(CNTs)相互搭接于内外两层MnO₂之间,作为一种导电中继,提高了复合材料的导电性。该复合材料具有优异的电化学性能：在0.1 A·g^-1的电流密度下,能够获得428.8 F·g^-1的可逆比电容,并在5 A·g^-1的高电流密度下仍能具有80%的电容保持率。同时,电极表现出优异的循环稳定性,在1 A·g^-1循环6000次之后比电容仅衰减5%。     

交联状聚苯胺包覆碳纤维复合纳米线 制备及电容特性

以交联状氮掺杂碳纳米纤维(CNF)为碳骨架,采用插层辅助原位氧化聚合法使聚苯胺(PANI)均匀地在CNF表面包覆生长,制备了交联状聚苯胺包覆碳纤维(PANI/CNF)复合纳米线。采用TEM、SEM、TG、FTIR、Raman、XRD、XPS和BET对PANI/CNF复合纳米线的形貌和结构进行了表征。通过CV、EIS和GCD测试了PANI/CNF复合纳米线的电容特性。结果表明:PANI/CNF复合纳米线相互连通,表面呈荆棘状,具有多级空间结构。CNF质量分数为40%的PANI/CNF40复合纳米线电极在电流密度为1.0 A/g时,比电容达到820.31 F/g。电流密度增加到20.0 A/g时,比电容保留率为74.8%。在10.0 A/g时,经过2000次充放电循环后电极的比电容保持率达到89.7%。     

Polyaniline/single-wall carbon nanotube (PANI/SWCNT) composites for high performance supercapacitors

PANI/SWCNT composites were prepared by electrochemical polymerisation of polyaniline onto SWCNTs and their capacitive performance was evaluated by means of cyclic voltammetry and charge-discharge cycling in 1 M H₂SO₄ electrolyte. The PANI/SWCNT composites single electrode showed much higher specific capacitance, specific energy and specific power than pure PANI and SWCNTs. The highest specific capacitance, specific power and specific energy values of 485 F/g, 228 W h/kg and 2250 W/kg were observed for 73 wt.% PANI deposited onto SWCNTs. PANI/SWCNT composites also showed long cyclic stability. Based upon the variations in the surface morphologies and specific capacitance of the composite, a mechanism is proposed to explain enhancement in the capacitive characteristics. The PANI/SWCNT composites have demonstrated the potential as excellent electrode materials for application in high performance supercapacitors.