三氧化钼/活性炭钠离子电化学电容器

以三氧化钼(MoO3)作为负极材料,活性炭(AC)作为正极材料,组成混合型电化学电容器.研究电容器在1 mol/L NaPF6的碳酸丙烯酯(PC)中的电化学性能,其电位窗为0～3V,能量密度和功率密度分达到33.0 W·h/kg和595.6W/kg,经1000次循环后容量为第20次的93.8％,库仑效率在经过20次循环后到95.1％以上.     

高比能高功率全石墨烯锂离子电容器

石墨烯由于拥有超高比表面积和超高电导率而被作为电化学电容器材料广泛研究.本文采用树脂为碳源，通过一种方便快捷的树脂交换法制备一种具有高比表面积的多级孔三维石墨烯（3DG）.经过此种方法的催化、造孔、热处理等主要工艺步骤后，可显著增加石墨烯材料的小、介孔数量，从而提高材料的电化学性能.通过BET测试表明，3DG的比表面积可达2400 m²/g，孔体积达到2.0 cm³/g.以3DG作为正负极材料制备高比能量高功率型锂离子电容器（3DG-LIC），可使3DG-LIC的工作电压从传统超级电容器的2.5 V扩展到4.0 V，能量密度也从20 Wh/kg提高到105 Wh/kg.另外，相同的化学和微观结构能很好地平衡正负极的容量及速率，使高比能量高功率的3DG-LIC具有更宽阔的应用领域.     

激光直写微型RGO/MWCNT/CF平面柔性超级电容器的制备及性能

将采用改性Hummers法制备的氧化石墨烯与多壁碳纳米管(MWCNT)复合, 通过激光直写的方法制备了以棉织物(Cotton fabric, CF)为基底的石墨烯复合碳纳米管的同心圆形织物柔性平面超级电容器(RGO/MWCNT/CF). 通过扫描电子显微镜、 X 射线衍射和拉曼光谱技术对RGO/MWCNT/CF进行了表征, 并对超级电容器的电导率和电化学性能进行了测试. 结果表明, 电极材料经激光还原后导电率达到了7.19×10 ⁴ S/m, 表现出良好的导电性能. 以RGO/MWCNT/CF为工作电极、 PVA/LiCl凝胶为电解质组装的超级电容器具有良好的电化学性能, 在电位窗口为0~1 V、 电流密度为40.8 mA/cm ²时比电容达到24 mF/cm ², 功率密度为61 mW·h/kg, 能量密度为1.22 mW·h/kg, 且循环1000次仍能保持92%的比电容.     

氮氧共掺杂多孔炭的制备及其锌离子混合超级电容器性能研究

本研究以价格低廉、来源广泛的煤沥青作为炭前驱体、尿素作为氮源和模板、氢氧化钠作为活化剂,通过结合模板法与化学活化法成功制备了具有纳米片状结构的氮氧共掺杂的多孔炭材料。多孔炭电极在0.05 A/g时最大比容量高达255.5 m A·h/g,在电流密度为1 A/g时,放电比容量达到78 m A·h/g。经过12000次循环,容量保持率仍有72.4%,并且能量密度最高达到99.6 W·h/kg,展现出作为正极材料的巨大潜力。以煤沥青为原料制备的氮氧共掺杂多孔炭材料作为锌离子混合超级电容器的正极材料表现出了优异的电化学性能。     

三氧化钼——一种新型有机系钠离子储能器件负极材料

由于锂资源短缺,我们尝试使用三氧化钼作为钠离子储能装置负极材料。通过一种简单的方法合成了三氧化钼,使用XRD、SEM和TEM等测试手段对其物性进行了表征。利用三氧化钼作为有机系钠离子储能器件的负极材料,通过循环伏安和恒流充放电测试探讨了负极材料的储钠机理。以三氧化钼(MoO3)作为负极材料,活性炭(AC)和石墨(graphite)作为正极材料,组装成新型的电化学储能器件,研究了两种器件在1mol/L NaPF6的碳酸丙烯酯(PC)中的电化学性能。两种器件的电压范围分别为0~3.2V和0~3.5V,能量密度最高可分别达到31.6和53 Wh/kg,长循环性能远远优于AC/AC对称电容器。此种储能装置有望成为锂离子电池的一个很好的替代。     

电致变色型导电聚苯胺固态超级电容器的构建与性能研究

以苯胺硫酸溶液为沉积液,导电玻璃(FTO)为基底材料,在-0.2~1.2 V范围内先电位扫描一圈生成聚苯胺(PANI)晶种,然后在-0.2~0.8 V范围内用循环伏安法电沉积导电PANI材料.所得样品用红外光谱和扫描电子显微镜进行结构表征;以最佳循环伏安电沉积条件制备的PANI/FTO为活性电极,以H_2SO_4/聚乙烯醇(H2SO4/PVA)为凝胶电解质组装了电化学电容器,通过循环伏安、恒电流充放电和电化学阻抗法研究了组装电化学电容器的电化学性能.研究结果表明,以H_2SO_4/PVA凝胶电解质,沉积于导电玻璃表面的PANI活性电极材料的面比电容可达172.7 m F/cm~2,并且在2000次充放电以后,比电容值仍可保留初始值的92.8%.以分区沉积有PANI的导电玻璃可组装制备通过变色显示充放电过程的电化学电容器,在充电时,其颜色逐渐从浅绿色向深绿色转变,放电时,颜色逐渐从深绿色向浅绿色转变.     

超级电容器用镍锰基二元金属氧化物电极材料

赝电容电容器相比于双电层电容器拥有更高的比容量(大约10~100倍),由于在充电/放电过程中法拉第反应同时在电极材料表面和内部发生。因此,会产生更多电子,拥有更大的比容量。目前,赝电容电极材料的研究主要集中在金属氧化物和导电聚合物。镍锰基金属氧化物具有较高的理论比容量、成本低、无毒、环境友好等优点,但是其实际的电化学性能远低于理论值。因此,为了提升材料的电化学表现,研究者提出许多有效的策略,例如:制备不同种类金属氧化物作为电极材料;采用不同的工艺制备高比表面积的材料以及不同材料之间的复合产生协同作用等。本文综述了镍锰基二元金属氧化物(NiMnO₃、NiMn₂O₄和Ni₆MnO₈)作为赝电容电极材料在超级电容器上的应用进展,同时结合目前研究方法进一步提出未来金属氧化物电极材料方面的发展方向,为继续深入研究提供一定的指导作用。     

WO3/碳布柔性非对称超级电容器的组装及性能研究

以超级电容器的电极材料制备、性质研究及对组装的非对称超级电容器的性能研究为核心内容,提高超级电容器电化学性能为主要目的,采用水热合成法在碳布基底上合成三氧化钨/碳布和活化后的碳布为超级电容器的电极材料。采用SEM、XRD表征方法对制备的材料进行了形貌表征及物相分析;使用上海辰华电化学工作站对电极材料进行了循环伏安、恒流充放电、交流阻抗等电化学性能测试. 最终得到以三氧化钨/碳布为正极材料、活化后的碳布为负极材料组装成不对称柔性电容器,进行电化学测试,其电位窗口提高到0~1.6 V,电流密度61.9 mA·cm^-2时,电容达到58.96 F·cm-2,功率密度0.48 W·cm^-2时,能量密度为20.36 mWh·cm^-2,同时在电流密度8 mA·cm^-2时,循环3000次时表现出良好的循环性能,相较于对称型超级电容器,倍率性能更加优异.     

超级电容器用无定形水合二氧化钌材料及Nafion作粘接剂的电极制备研究(英文)

本文采用改性的中和反应和随后的热处理方法制备了较大产量的超级电容器用无定形水合二氧化钌材料(RuO2·0.93H2O),同时,制作了电极进行了电化学性能表征。实验中,以自制的喷雾装置和十二烷基磺酸钠(SDS)分别作为反应辅助技术和表面分散剂,经175℃处理前驱体后,获得了比表面积为223m2/g、蓬松状、深黑色无定形水合二氧化钌材料。研究了以Nafion为粘结剂和以碳纤维纸为集流体所制备电极的电化学性能。循环伏安实验(CV)结果表明,该合成材料具有较好的比电容(988F/g at 1mV/s)和倍率特性;电化学交流阻抗(EIS)实验进一步证明了该材料具有较低的等效串联内阻(~30mΩ)和频率响应特性。合成材料有望在国防及民用领域超级电容器中得到规模化应用。     

海藻基含杂原子碳材料的制备及电化学性质

以天然海藻为原料,经条件优化制备了含杂原子的碳材料Sar CW-900及Lam CW-900,对其形貌、元素成分、孔性质和石墨化程度进行分析并讨论其活化机理.将2种材料作为电化学电容器及锂离子电池的电极材料活性物质,分别进行电化学性能测试.结果表明,Sar CW-900及Lam CW-900在被用作电化学电容器电极材料时,比电容分别为106 F/g及85 F/g,经5000次循环伏安稳定性测试,比电容值稳定在101 F/g及81 F/g,分别降低不到4%和5%,是理想的电容器电极材料;在被用作锂离子电池电极材料时,经100次循环比容量分别保持在100. 3及33. 9 mA·h/g,低于纯石墨的理论值,但具有较高的稳定性.     

Hydrous manganese oxide/carbon nanotube composite electrodes for electrochemical capacitors

A novel type of composite electrode based on hydrous manganese oxide and a single-walled carbon nanotube has been prepared and used in electrochemical capacitors. Cyclic voltammetry, galvanostatic charging/discharging tests and electrochemical impedance measurements were applied to investigate the performance of the composite electrodes with different ratios of hydrous manganese oxide and single-walled carbon nanotube. For comparison, the performance of pure hydrous manganese oxide and pure carbon nanotubes was also studied. In this way, the composite electrode with a 6:4 ratio of hydrous manganese oxide to carbon nanotube was found to be the most promising active material for an electrochemical capacitor, which shows both good capacitance and power characteristics.     

Chitin and chitin-cellulose composite hydrogels prepared by ionic liquid-based process as the novel electrolytes for electrochemical capacitors

This paper reports on the preparation and electrochemical performance of chitin- and chitin-cellulose-based hydrogel electrolytes. The materials were prepared by a casting solution technique using ionic liquid-based solvents. The method of chitin dissolution in ionic liquid with the assistance of dimethyl sulfoxide co-solvent was investigated. The obtained membranes were soaked with 1-M lithium sulfate aqueous solution. The prepared materials were preliminarily characterized in terms of structural and physicochemical properties. Further, the most promising biopolymer membranes were assembled with activated carbon cloth electrodes in symmetric electrochemical capacitor cells. The electrochemical performances of these devices were studied in a 2-electrode system by commonly known electrochemical techniques, such as cyclic voltammetry, galvanostatic charge/discharge, and electrochemical impedance spectroscopy. The devices operated at a maximum voltage of 0.8 V. All the investigated materials have shown high efficiency in terms of specific capacitance, power density, and cyclability. The studied capacitors exhibited specific capacitance values in the range of 92–98 F g⁻¹, with excellent capacitance retention (ca. 97–98%) after 20,000 galvanostatic charge and discharge cycles. Taking into account the above information and the eco-friendly nature of the biopolymer, it appears that the prepared chitin- and chitin-cellulose-based hydrogel electrolytes can be promising components for green electrochemical capacitors.

     

N-CNTs/NiCo-LDH复合材料的制备及电化学性能

通过高温碳化聚吡咯纳米管制备了氮掺杂碳纳米管(N-CNTs), 并采用共沉淀法将镍钴层状双氢氧化物(NiCo-LDH)原位生长在N-CNTs上, 制备出具有三维互联网状结构的N-CNTs/NiCo-LDH复合材料. 研究了镍钴摩尔比对N-CNTs/NiCo-LDH复合材料形貌结构和电化学性能的影响. 结果表明, 当镍钴摩尔比为1∶2时, N-CNTs/Ni₁Co₂-LDH具有最佳的电化学性能. 在1 A/g电流密度下, 其比电容可达1311.8 F/g; 当电流密度为 10 A/g时, 电容保持率高达88.3%, 展现出优异的倍率性; 在经过2500次循环后, 电容保持率仍可达76.4%, 具有良好的循环稳定性.由N-CNTs/Ni₁Co₂-LDH与活性炭(AC)电极所构建的N-CNTs/Ni₁Co₂-LDH//AC水系混合型超级电容器, 在750 W/kg功率密度下, 具有27.19 W·h/kg的高能量密度.     

以预锂化中间相碳微球为负极的锂离子电容器的电化学性能

以商品活性炭(AC)为正极, 预锂化中间相碳微球(LMCMBs)为负极, 组装成锂离子电容器(LICs). 用X射线衍射(XRD)对LMCMB 电极材料的晶体结构进行了表征和分析, 预锂化量(PIC)小于200 mAh·g^-1 时,LMCMB电极材料基本保持了原始的石墨晶体结构. 利用三电极装置, 测试了充放电过程中LICs 的正、负极及整电容器的电压变化曲线. 以LMCMB为电极, 锂离子电容器负极的工作电压变低, 并且电压曲线更加平坦, 同时正极也可以利用到更低的电压区间. 对比锂离子电容器MCMB/AC, LMCMB/AC在比能量密度、循环性能和库仑效率电化学性能方面都得到了改善. 在电压区间2.0-3.8 V 下, 100 次循环后, 放电比容量的保持率从74.8%增加到100%, 库仑效率从95%增加到100%. LMCMB/AC电容器容量不衰退的直接原因是由于AC正极极化变小. 在2.0-3.8 V和1.5-3.8 V电压区间内, LMCMB/AC锂离子电容器的比能量密度分别可达85.6和97.9 Wh·kg^-1.     

聚3-(4-氟苯基)噻吩/碳化聚丙烯腈泡沫复合电极的电化学研究

噻吩衍生物是合成导电高分子材料的单体之一,在有机电致发光器件和电能存储等方面有着广泛的应用。聚3-(4-氟苯基)噻吩(PFPT)是一类既可进行p型掺杂又可进行n型掺杂的窄能带聚合物,在导电高分子型电化学电容器方面具有很好的应用前景,聚丙烯腈微孔膜已在锂离子电池方面有了很好的应用。若将它与碳纸复合后,再进行高温碳化和CO2活化,可制得导电性好、比表面积大的片状材料,作为电化学电容器的电极材料具有一定的双电层电容量．本文在三电极电解池中以这种材料的薄片为工作电极使3-(4-氟苯基)噻吩在乙腈溶液中进行电化学聚合,制备了聚3-(4-氟苯基)噻吩／碳化聚丙烯腈泡沫复合电极并研究了电极的电化学特性。     

用于超级电容器的锰钴氧化物/碳纤维材料

The development of high-performance supercapacitor electrode materials is imperative to alleviate the ongoing energy crisis. Numerous transition metals (oxides) have been studied as electrode materials for supercapacitors owing to their low cost, environmental-friendliness, and excellent electrochemical performance. Among the developed binary transition metal oxides, manganese cobalt oxides typically show high theoretical capacitance and stable electrochemical performance, and are widely used in the electrode materials of supercapacitors. However, the poor conductivity and active material utilization of manganese cobalt oxide-based electrode materials limit their potential capacitance application. Cotton is mainly composed of organic carbon-containing materials, which can be transformed to carbon fibers after calcination. The resultant carbonaceous material exhibits a large specific surface area and good conductivity. Such advantages could potentially suppress the negative effects caused by the poor conductivity and small specific surface area of manganese cobalt oxides, thereby improving the electrochemical performance. Herein, we firstly deposited manganese cobalt oxides on cotton by a simple hydrothermal method, yielding a composite of manganese cobalt oxides and carbon fibers via subsequent calcination, to improve the electrochemical performance of the electrode material. X-ray diffraction (XRD), field-emission scanning electron microscopy (FESEM), X-ray photoelectron spectroscopy (XPS), Brunauer-Emmett-Teller (BET), thermogravimetric analysis (TGA), and electrochemical characterizations were used to investigate the physical, chemical, and electrochemical properties of the prepared samples. The fabricated manganese cobalt oxides in the composite were uniformly dispersed on the carbon fiber surface, which increased the contact between the interface of the electrode material and electrolyte, and enhanced electrode material utilization. The electrode material was confirmed to have well contacted with the electrolyte during a contact angle test. Hence, a pseudo-capacitance reaction completely occurred on the manganese cobalt oxide material. Moreover, the addition of carbon fibers reduced the resistance of the material, resulting in excellent capacitive performance. The capacitance of the prepared composite was 854 F∙g^-1 at a current density of 2 A∙g^-1. The capacitance was maintained at 72.3% after 2000 cycles at a current density of 2 A∙g^-1. These results indicate that the manganese cobalt oxide and carbon fiber composite is a promising electrode material for high-performance supercapacitors. The findings presented herein provide a strategy for coupling with carbon materials to enhance the performance of supercapacitor electrode materials based on manganese cobalt oxides. Thus, novel insights into the design of high-performance supercapacitors for energy management are provided.     

Electrochemical behavior of some purine derivatives on carbon based electrodes

The electrochemical behaviour of three purine derivatives was investigated by cyclic voltammetry on different electrode materials: glassy carbon in native form and electrochemically activated, carbon paste electrode unmodified or modified with 1, 4-benzoquinone. The preliminary study obtained on solid electrodes was extended to graphite based planar screen-printed electrodes, unmodified and modified with multi-wall carbon nanotubes, or cobalt phthalocyanine.     

Relation between the ion size and pore size for an electric double-layer capacitor

The research on electrochemical double layer capacitors (EDLC), also known as supercapacitors or ultracapacitors, is quickly expanding because their power delivery performance fills the gap between dielectric capacitors and traditional batteries. However, many fundamental questions, such as the relations between the pore size of carbon electrodes, ion size of the electrolyte, and the capacitance have not yet been fully answered. We show that the pore size leading to the maximum double-layer capacitance of a TiC-derived carbon electrode in a solvent-free ethyl-methylimmidazolium-bis(trifluoro-methane-sulfonyl)imide (EMI-TFSI) ionic liquid is roughly equal to the ion size (approximately 0.7 nm). The capacitance values of TiC-CDC produced at 500 degrees C are more than 160 F/g and 85 F/cm(3) at 60 degrees C, while standard activated carbons with larger pores and a broader pore size distribution present capacitance values lower than 100 F/g and 50 F/cm(3) in ionic liquids. A significant drop in capacitance has been observed in pores that were larger or smaller than the ion size by just an angstrom, suggesting that the pore size must be tuned with sub-angstrom accuracy when selecting a carbon/ion couple. This work suggests a general approach to EDLC design leading to the maximum energy density, which has been now proved for both solvated organic salts and solvent-free liquid electrolytes.     

Electrochemical behavior of activated carbon electrodes in electric double layer capacitors with tetrametylammonium bis(oxalato)borate electrolyte synthesized by microwave irradiation

The electrochemical behavior of electric double layer capacitors (EDLCs) with tetramethylammonium bis(oxalato)borate electrolyte and electrodes based on various activated carbons (ACs) was studied. Tetraalkylammonium bis(oxalate)borate salts were synthesized by means of microwave (MW) irradiation. The specific conductivities of salt solutions were determined. It was shown that the efficiency of electric double layer capacitors increases with an increase in specific surface area and a decrease in the purity of carbon materials.     

絮状三元镍钴铁氢氧化物电极材料的制备及其电化学储能性能

采用一步溶剂热法在泡沫镍(NF)基底上合成了镍钴氢氧化物、镍铁氢氧化物及镍钴铁氢氧化物3种电极材料,并对其电化学性能进行测试,结果表明:三元镍钴铁金属电极的储能性能要远大于其他2种二元金属电极,其在2 mA·cm-2电流密度下能达到5.11 F·cm-2的面积比电容,并且构筑的非对称超级电容器在功率密度为46.814 ...