碳基有机电解液超级电容器性能研究

为了提高碳基有机电解液超级电容器的容量，对电容器电极中的导电剂、粘结剂含量以及电极成型压力对超级电容器的比容量的影响进行了研究．通过对等效电路和交流阻抗图谱的模拟分析，研究了电极电阻、极化电阻、扩散电阻、双电层电容、极限容量等参数与导电剂、粘结剂含量的关系．确定了导电剂和粘结剂的最佳含量．对优化后使用组装的超级电容器，采用循环伏安和恒电流充、放电的方法，对超级电容器的工作电压、容量、循环寿命、漏电电流进行了测量．结果表明：该超级电容器工作电压可达到3V，电容器的比容量可达到31．78F／g，电容器循环5000次以后，容量衰减1．26％．     

氧化镍/活性炭电极的超电容性能

在制作双电层电容器基础上,采用电化学沉积法,在活性炭电极表面负载氧化镍.XRD测定表明,镍氧化物以NiO形态负载于活性炭电极上.电化学性能研究表明,氧化镍/活性炭复合电极循环伏安曲线呈矩形特征,具有良好的电容特性;其交流阻抗谱由圆弧和直线组成,电化学过程受扩散和氧化镍的赝电容行为控制;其恒电流充电曲线呈直线,电容特性显著,大电流性能良好,比容量达104.7 F/g,是活性炭电极比容量的1.35倍.     

活性炭比表面积对双电层电容特性的影响

用KOH活化活性炭作为电极材料制作双电层电容器,用接触角测定其润湿性,用恒流充放电、循环伏安等方法研究活性炭的电化学性能。结果显示,炭膜浸润时间最短约为90min,双电层电容器的比电容随比表面积增加而增大。比表面积为1932m^2·g^-1的炭样在1mol·L^-1的H2SO4电解~（677mA·g^-1）中充放电最大比电容为167F·g^-1。     

β-Ni(OH)2/C混合超级电容的电极行为

分别利用β-Ni(OH)2和活性炭为正、负极活性物质，通过循环伏安和双电极恒流充放电测试考察了镍正极与碳负极组合成混合超级电容电极在KOH电解液中的电极行为，结果表明，镍正极的法拉第电化学反应过程和碳负极非法拉第双电层过程可以很好的结合起来，体现出超级电容的充放特性，对于碳电极对，由于正极容量的限制，使得工作电压仅为1V左右，双电极比容量为39．6F/g，而镍正极／碳负极组合工作电压可高达1．5V，双电极比容量能达到90．7F/g，在相同电流下进行放电，镍／碳电极对功率密度可达到碳电极对的2－3倍，能量密度可高达10倍。     

基于碳纳米管的双电层电容器

碳纳米管由于具有良好的导电性、较高的比表面积、优良的化学稳定性。因而被认为是超级电容器的理想电极材料，本文制备了基于碳纳米管的双电层电容器，其比容量为21F/g，等效电阻为2Ω，漏电流为1.5mA，同活性炭相比，碳纳米管电极因为独特的孔隙结构而具有高的比表面积利用率和低的等效电阻，在高功率大容量电容器方面有着广阔的应用前景。     

NiO/AC非对称超级电容器的研究

通过热处理球形Ni（OH）2得到NiO粉末，将其作为正极与活性炭（AC）负极组装成非对称超级电容器，用恒流充放电测试分析了超级电容器的电容特性。讨论了正负极活性物质比例、充放电电流和热处理时间对超级电容器比电容量、内阻的影响。结果表明：正负极活性物质比为1：3，工作电流密度为200mA／g，当Ni（OH）2的热处理时间为2h，充电电压为1．3V时，超级电容器的双电极比电容量可达71．5F／g。     

（NiO＋CoO）／活性炭超级电容器电极材料的制备及其性能

以表面包覆7％Co（OH）2的球形Ni（OH）2为原料,在450℃热分解得到（NiO＋CoO）粉末,将其与活性炭（AC）按不同质量比混合均匀,得到超级电容器用（NiO＋CoO）／AC复合电极材料。采用扫描电镜（SEM）、X射线衍射（XRD）、热重分析（TG）等方法对样品进行物理性能测试,用循环伏安（Cv）法研究不同配比的（NiO＋CoO）／AC复合电极在6mol／LKOH电解液中的电化学性能,并对复合电极材料模拟电容器与活性炭模拟电容器进行恒流充放电测试。研究结果表明：在6mol／LKOH电解液中,当复合材料中的（NiO＋CoO）质量分数为6％时,所制备的单电极比电容量最大,为240V／g,比纯活性炭电极的比电容（约160F／g）提高50％：复合电极模拟电容器具有较好的可逆性和电化学性能。     

碳基凝胶聚合物电解质双电层电容器的研究

为了克服液体电解液电容器的漏液和安全问题,以活性炭作电极材料,丙烯腈作聚合物单体,分别以碳酸丙烯酯 碳酸乙烯酯、碳酸二甲酯 碳酸乙烯酯和碳酸甲乙酯 碳酸乙烯酯的混合液作增塑剂,高氯酸锂为支持电解质盐,采用内聚合法制备了PAN基凝胶聚合物电解质双电层电容器(GPE-EDLCs).采用交流阻抗法测量了凝胶聚合物电解质(GPE)的离子电导率.采用交流阻抗、循环伏安、恒流充放电等测试方法研究了GPE-EDLCs的性能,并与有机电解液双电层电容器(LOE-EDLCs)进行了比较.结果表明,PAN基GPE的电导率在室温下为6.51～8.94 mS·cm-1,PAN基GPE-EDLCs的工作电压为2.5 V,电容器的比容量为43.9～47.4F/g(i=0.5 mA/cm2),能量密度为128.8～148.1 J/g,与LOE-EDLCs性质相近.     

水系和有机系活性炭超级电容器的性能研究

采用活性炭作为电极活性物质,以碳纳米管为导电剂,用聚四氟乙烯隔膜制备水系和有机系扣式超级电容器,考察并分析二者在容量特性、自放电性能、循环性能、功率密度、能量密度等方面的优劣。结果表明,实验制得的电容器样品表现出良好的电容行为和循环性能;水系电容器样品10h自放电率为28.7%,1h漏电流为0.32mA;有机系电容器样品在电流密度为1.04A/g时,能量密度为10.32Wh/kg,功率密度达到1.88kW/kg。     

电极用金属活性炭的催化制备与表征

采用催化活化法制备了含有不同种类和数量金属的金属活性炭,利用氮气吸附、扫描电子显微镜、定电流充放电等方法表征了金属活性炭的结构、形貌和电化学性能,并考察了金属种类和数量对活化烧失率以及活性炭形貌、孔结构、吸附性能和电容量的影响．结果表明,金属催化活化法有利于活性炭孔隙率的提高,在1．8nm以下的微孔和3．4～4．2nm范围的中孔数量增加幅度最为明显,但对孔径分布影响不大;金属活性炭的中孔以墨水瓶状孔隙为主,不利于对较大分子吸附质的吸附,但金属活性炭具有提供双电层电容和准电容的双层功效,是制作超级电容器电极的适宜材料．     

Performance of a combined capacitor based on ultrafine nickel oxide／carbon nanotubes composite electrodes

A new sol-gel process for the preparation of ultrafine nickel hydroxide electrode materials was developed. The composite electrodes consisting of carbon nanotubes and Ni(OH)2 were developed by mixing the hydroxide and carbon nanotubes together in different mass ratios. In order to enhance energy density, a combined type pseudocapacitor/electric double layer capacitor was considered and its electrochemical properties were characterized by cyclic voltammetry and dc charge/discharge test. The combined capacitor shows excellent capacitor behavior with an operating voltage up to 1.6 V in KOH aqueous electrolyte. Stable charge/discharge behaviors were observed with much higher specific capacitance values of 24 F/g compared with that of EDLC (12 F/g) by introducing 60% Ni(OH)2 in the anode material. By using the modified anode of a Ni(OH)E/Carbon nanotubes composite electrode, the specific capacitance of the cell was less sensitive to discharge current density compared with that of the capacitor employing pure nickel hydroxide as anode. The combined capacitor in this study exhibits high energy density and stable power characteristics.     

球磨对多壁纳米碳管束电化学容量的影响

为了提高纳米碳管电极在电化学双电层电容器（EDLC）中的电化学性能，研究了球磨处理对高纯度多壁纳米碳管(MWNT)束电极电化学容量的影响.将球磨处理前后的两种MWNTs分别制作成电极,并组装成模拟EDLC，利用循环伏安法和恒流充放电法，测试MWNT电极的电化学可逆容量.研究结果表明，MWNT粗产品的纯度达到了97%以上.经过3 h的球磨处理后，大多数MWNTs束被打散或打断，其比表面积由球磨前的238 m2/g提高到了340 m2/g. 用MWNTs制备的EDLC电化学容量由球磨前的36 F/g提高到了72 F/g.与球磨前的MWNTs束相比，球磨后的样品更适合作为EDLC电极材料.     

Synthesis of novel ordered carbon nanorods and its application in electrochemical double layer capacitor

A unit cell of EDLC works on the principle of double-layer capacitance at the elec- trode/electrolyte interface where electric charges are accumulated on the electrode sur- faces and ions of opposite charge are arranged in the electrolyte side. EDLC is character- ized by its high capacitance, small leaking current, simple charge-discharge, high power output and long cycle life, etc. The capacitance of EDLC is about 20―200 times of tra- ditional capacitor and applicable in a wide temperatu…     

载镍活性炭材料及复合型超级电容器

为提高碳基电化学电容器的比电容和和能量密度,采用化学沉积法将少量镍氧化物沉积在活性炭上,得到沉积镍氧化物的活性炭材料并以此材料做成复合电极用于混合型电化学电容器的正极.研究显示,沉积镍氧化物后,碳材料的比表面积略有减小,但孔径分布没有明显变化.复合电极作为混合型电容器的正极时,比电容达到194.01F/g,比纯活性炭正极的175F/g提高了10.84%;复合电极在6mol/L的电解液中析氧电势为0.296V,比纯活性炭电极的0.220V高出0.076V,因此,具有较高的能量密度.不同放电电流密度下的恒电流测试结果显示,沉积镍氧化物活性炭复合电极的比电容值没有明显变化,与纯活性炭电极一样表现出良好的功率特性.采用沉积镍氧化物活性炭作为正极材料的复合型电容器,在6mol/L的KOH水溶液作为电解液时,单体电容器的工作电压可以达到1.2V,高于纯活性炭制备的双层型电容器0.2V.充放电循环10000次时,复合型电容器的电容仅降低到初始电容的90%.上述结果表明,在活性炭上沉积少量镍氧化物颗粒可以提高碳基电化学电容器的比电容和能量密度.     

NiAl-LDHs 电极材料的水热合成及其超级电容器电化学性能

超级电容器具有大充放电速率、良好的循环稳定性及高功率密度等优点, 是一种新兴的绿色环保储能器件。采用简单的水热合成法制备镍铝层状双金属氢氧化物(NiAl-LDHs) 超级电容器电极材料, 探究不同镍铝比对其形貌组成及电化学性能的影响。所制备的Ni₁Al₁-LDHs 电极材料在电流密度为1 A/g 时表现出378 F/g 的高比电容。以活性炭(AC) 为负极组成的Ni₁Al₁-LDHs//AC 非对称超级电容器在能量密度为27.5 Wh/kg 时, 具有1.4 kW/kg 的高功率密度, 表现出优异的电化学性能。     

Preparation and properties of pitch carbon based supercapacitor

Using the mesophase pitch as precursor, KOH and CO2 as activated agents, the activated carbon electrode material was fabricated by physical-chemical combined activated technique for supercapacitor. The influence of activated process on the pore structure of activated carbon was analyzed and 14 F supercapacitor with working voltage of 2.5 V was prepared. The charge and discharge behaviors, the properties of cyclic voltammetry, specific capacitance, equivalent serials resistance (ESR), cycle properties, and temperature properties of prepared supercapacitor were examined. The cyclic voltammetry curve results indicate that the carbon based supercapacitor using the self-made activated carbon as electrode materials shows the desired capacitance properties. In 1 mol/L Et4NBF4/AN electrolyte, the capacitance and ESR of the supercapacitor are 14.7 F and 60 m?, respectively. The specific capacitance of activated carbon electrode materials is 99.6 F/g; its energy density can reach 2.96 W·h/kg under the large current discharge condition. There is no obvious capacitance decay that can be observed after 5000 cycles. The leakage current is below 0.2 mA after keeping the voltage at 2.5 V for 1 h. Meanwhile, the supercapacitor shows desired temperature property; it can be operated normally in the temperature ranging from -40 ℃ to 70 ℃.     

Influence of polyethylene glycol on pore structure and electric double-layer capacitance of carbon xerogel

Mesoporous polyethylene glycol-resorcinol and formaldehyde(PEG-RF) carbon xerogels were prepared by a new polymer blend method in which PEG-RF mixed organic xerogels were synthesized by blending thermally unstable polyethylene glycol with organic monomers, resorcinol and formaldehyde and then subjected to pyrolization at 1 000℃. The influences of mass ratio of PEG to the theoretical yield of RF xerogel, m(PEG)/m(RF) and the relative molecular mass of PEG on the pore structure and electric double layer capacitance(EDLC) performance of PEG-RF carbon xerogels were investigated. The results show that PEG under different conditions leads to the difference of phase separation structure of the polymer blend and thus the change of pore structure of PEG-RF carbon xerogels. Specific surface area and capacity of PEG-RF carbon xerogels in 300/60 H2SO4 solution can reach 755 m^2/g and 150 F/g, respectively. Their surface can be fully utilized to form electric double layer. However, the pore structure differences of PEG-RF carbon xerogels result in their different EDLC performances. The distributed capacitance effect increases with decreasing the pore size of PEG-RF carbon xerogels.     

Electrochemical performance of nickel oxide／KOH／active carbon super-capacitor

The fabrication and characterization of new type Nickel oxide/KOH/Active carbon super-capacitor have been described. Porous nickel oxide was prepared by hydrolysis of nickel acetate and heated in air at 300℃. The resulting nickel oxide behaved as an electrochemical capacitor electrode with a specific capacitance (50-70 F/g) superior to most active carbon electrodes. This kind of nickel oxide maintained high utilization at high rate of discharge (i.e., high power density) and had excellent cycle life more than 1 000 times,while the capacitance of the cell composed of two identical nickel oxide electrodes was poor at high discharge current density and the maximum operational voltage of this type capacitor was limited to 0.5 V. A new type super-capacitor was designed in which the nickel oxide and the active carbon were applied to the positive and negative electrodes respectively. The breakdown voltage of this type super-capacitor was improved effectively to 0.8 V and excellent characteristic of high power discharge was attained in this way. The Nickel oxide/KOH/Active carbon super-capacitor has promising potentials in portable telecommunications, uninterruptable power supplies and battery load leveling applications.     

Pseudo-capacitance of ruthenium oxide/carbon black composites for electrochemical capacitors

Hydrous ruthenium oxide was formed by a new process. The precursor was obtained by mixing the aqueous solutions of RuCl3·xH2O and NaHCO3. The addition of NaHCO3 led to the formation of an oxide with extremely fine RuO2 particles forming a porous network structure in the oxide electrode. Polyethylene glycol was added as a controller to partly inhibit the sol-gel reaction. The rate capacitance of 530 F·g-1 was measured for the powder formed at an optimal annealing temperature of 210°C. Several details concern...