核桃壳化学-物理耦合活化法制备活性炭及其表征

采用植物废弃物核桃壳为原料,以化学-物理耦合活化法制备了核桃壳活性炭,考察了磷酸浓度、活化温度、活化时间对核桃壳活性炭碘值、亚甲基蓝吸附值和烧失率的影响。结果表明,最佳制备条件为:磷酸质量分数85%,活化温度900℃,活化时间3h。在此制备条件下,核桃壳活性炭的比表面积为1 241.81m2·g-1,吸附累积总孔容为0.90cm3·g-1,最可几孔径分布为1.62nm。采用扫描电子显微镜、透射电子显微镜、比表面积测定仪以及红外光谱仪对核桃壳活性炭的表面形貌、孔结构及表面官能团进行了分析。     

含油污泥制备高比表面积活性炭

以含油污泥为原料,氢氧化钠为活化剂,在氮气保护下,通过室内静态热解炉制备高比表面积活性炭。研究炭化温度、活化升温方式、活化温度、活化时间和碱碳质量比m(NaOH)／m(C)对高比表面活性炭的影响。采用全自动比表面与孔隙度分析仪、钨灯丝环境扫描电子显微镜等测试设备,分别对产品的比表面积与孔径分布、组成及微观形貌进行定性或定量分析。研究结果表明,含油污泥制备高比表面积活性炭的较佳条件为:炭化温度500℃,活化升温方式(c),活化温度800℃,活化时间1h, m(NaOH)／m(C)=2。采用本方法制备的活性炭比表面积大于2000m2/g,平均孔径小于2nm,总孔容大于2cm3/g,性能优于普通活性炭,可作为能源储存介质、电极材料、高效吸附剂的基础材料,为含油污泥的资源化利用提供了一条新途径。     

微孔活性炭纤维的制备及性能研究

以沥青基炭纤维为原料,采用（H2O＋CO2）物理活化的方法制备出微孔活性炭纤维（ACF）,研究了制备工艺对活性炭纤维微孔结构及性能的影响.结果表明：活化温度和时间对活性炭纤维比表面积影响较大;随着活化温度的升高,活性炭纤维的比表面积明显提高;在一定温度下活化时,活化初始阶段比表面积增加较快,活化一定时间后比表面积升高趋势变缓.铵盐浸渍处理加快了活化反应的进行,使活性炭纤维比表面积明显升高,孔径增大.     

含铜活性炭电极材料的制备及电化学性能研究

以烟煤为原料,采用金属催化法制备了具有较大中孔率的含铜活性炭电极材料,测定、比较了氧化铜、普通活性炭和含铜活性炭为原料所制备电极的循环伏安、定电流充放电、交流阻抗等电化学性能,探讨了含铜活性炭电极的电容产生机理.结果表明,活性炭电极中含有适量的铜可与活性炭产生协同效应,表现出较好的功率特性、容量特性和较小的阻抗;添加硝酸铜20%（以铜计）的活性炭具有大电流放电的特性;添加硝酸铜40%（以铜计）的活性炭比容量可达92.5F/g,是无铜活性炭比电容量的2.35倍.     

物理化学两步活化法制备煤基活性炭电极材料

为提高超级电容器用的活性炭电化学性能,通过物理化学两步活化法制备煤基活性炭.以太西无烟煤为原料,通过成型和炭化后,用CO_2物理活化制得柱状活性炭(AC-1).将AC-1酸洗脱灰,并用KOH水溶液浸渍,进行第2步化学活化,制得超级电容器用的煤基活性炭(AC-2),两步活化后总收率为45.18%.将活性炭制备成电极材料,并在三电极和双层电容器体系下进行电化学性能测试.结果表明:在KOH电解液浓度为6mol/L,电流密度为0.5A/g时,三电极体系下,比电容由68.5F/g(AC-1)提高到122.5F/g(AC-2),在纽扣式超级电容器体系下,比电容由75F/g(AC-1)提高到165.5F/g(AC-2),且AC-2具有良好的长循环稳定性,经过5 000次的循环后电容量几乎无衰减.与物理活化所得活性炭相比,物理化学两步活化所得活性炭的总孔容和中孔率明显增加,其作为电极材料的电化学性能显著提高.     

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.     

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．     

孔结构对煤基活性炭电化学性能的影响

以煤为前驱体,KOH为活化剂制备系列煤基活性炭电极材料.采用N_2吸附法及电化学测试对活性炭的孔结构和电化学性能进行了表征,研究了孔结构对活性炭电极材料的电化学性能的影响.结果表明,采用化学活化法可制备出比表面积1 048～3 581 m~2/g、中孔率7%～91%的活性炭电极材料.在3 mol/L KOH无机电解液体系及1 mol/L(C_2H_5)_4NBF_4/碳酸丙烯酯(PC)有机电解液体系中,活性炭电极材料的比电容分别达到322 F/g,190 F/g.2～3 nm的中孔对电解质离子在电极材料中的扩散有着重要作用,可以有效降低电解液的扩散阻力,提高电极材料比表面积的利用率,从而增强电容器的电化学性能.     

石油焦制备高比表面积活性炭技术的研究

研究了以石油焦为原料、KOH化学活化法制备高比表面积活性炭工业化技术,以及工业化制备中碱炭比、活化温度、活化时间对产品指标的影响,提出了适合高比表面积活性炭工业化的新型反应器及碱液回收处理工艺,确定了生产高比表面积活性炭的最佳工艺条件：碱炭比5、活化温度830℃、活化时间1．0h．结果表明,采用确定的技术路线可实现高比表面积活性炭的工业化,采用确定的工艺条件可工业化制备BET比表面积达2900m^2/g、平均孔径2．46nm的活性炭产品。     

两电极体系新型全固态电极特性分析与应用

为提高两电极体系检测仪器的稳定性,采用具有极大比表面积的活性炭电极作为全固态对电极构成新型两电极体系检测仪器,并对该仪器特性进行一系列分析.研究考察活性炭电极的超级电容特性和电极电位稳定性,以铂、玻碳电极为工作电极,新型全固态活性炭电极为对电极,构建两电极体系水质检测仪器,并应用于水体中双氧水与铅离子的检测.结果表明,该检测仪器的灵敏度、检出限、检测范围均取得了与三电极体系类似的检测结果.采用活性炭对电极的固态电极具有电位稳定、化学惰性、价格低、易于小型化、易于使用和维护等优点,使构建的两电极水质检测仪器结构简单、可靠性高,具有较好应用前景.     

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 ℃.     

Effect of Adding Microwave Absorber on Structures and Properties of Hypercoal-Based Activated Carbons

Using lignite-based hypercoal as raw material,KOH as activator and CuO as microwave absorber,we prepared hypercoal-based activated carbons by microwave-assisted activation.The pore structure and the electrochemical performance of the activated carbons were tested,and the effects of adding CuO in the activation reaction process were also investigated.The activated carbons prepared were characterized by nitrogen adsorption-desorption,X-ray diffraction (XRD) and scanning electron microscopy (SEM).The specific surface area and mesoporous ratio of the hypercoal-based activated carbon are 1 257 m~2/g and 55.4%,respectively.When the activated carbons are used as the electrode materials,the specific capacitance reaches 309 F/g in 3 M KOH electrolyte.In comparison with those prepared without CuO absorber,the specific capacitance increases by 11.6%.It was proved that the addition of microwave absorber in microwave-assisted activation was a low-cost method for rapidly preparing activated carbon,and it could effectively promote the development of the pore structure and improve its electrochemical performance.     

Influence of KOH activation techniques on pore structure and electrochemical property of carbon electrode materials

1 INTRODUCTIONSupercapacitor is a kind of newenergy storagedevice , which can fill the gap between the conven-tional capacitor and the battery[1 ,2]. Supercapa-ciors are nowutilizedin many fields ,such as spaceindustry ,national defense ,warindustry ,electricalvehicle , wireless communication, and consume e-lectronics .It is well known that the electrode ma-terial is the key factor to determine the perform-ance of supercapacitor . At present ,the activatedcarbonis the main marketed availa…     

Synthesis of mesoporous carbon as electrode material for supercapacitor by modified template method

The pore structures and electrochemical performances of mesoporous carbons prepared by silica sol template method as electrode material for supercapacitor were investigated. The mean pore size and mass specific capacitance of the mesoporous carbons increase with the increase of mass ratio of silica sol to carbon source （glucose）. A modified template method, combining silica sol template method and ZnCl2 chemical activation method, was proposed to improve the mass specific capacitance of the mesoporous carbon with an improved BET surface area. The correlation of rate capability and pore structure was studied by constant current discharge and electrochemical impedance spectroscopy. A commercially available microporous carbon was used for comparison. The result shows that mesoporous carbon with a larger pore size displays a higher rate capability. Mesoporous carbon synthesized by modified template method has both high mass specific capacitance and good rate capability.     

微波活化甘蔗渣合成活性炭及其电化学电容特性

以甘蔗渣为原料,ZnCl2为活化剂,分别采用微波加热活化和管式炉加热活化制备了一系列活性炭材料,并研究了微波活化法制备的活性炭在水或离子液体电解液体系中的电容特性.氮气吸附测试表明:活化剂的浓度与活性炭的孔结构密切相关,加热方式对孔径结构的影响不大,但微波活化法在加热效率和均匀性方面具有明显的优势.当活化剂的浓度从20wt%增大到60wt%时,活性炭的平均孔径从2.5nm逐渐增大到7.0nm.电化学测试表明:在离子液体中炭材料的电容性能与其孔径大小密切相关,孔径尺寸越大,其电容性能越好.离子液体电容器能提供远高于水相电容器的能量密度.AC60在功率密度为2.5kW/kg时,仍能提供9.2Wh/kg的能量密度.     

High-performance porous carbon for supercapacitors prepared by one-step pyrolysis of PF/gelatin blends

A high-performance porous carbon material for supercapacitor electrodes was prepared by using a polymer blend method. Phenol-formaldehyde resin and gelatin were used as carbon precursor polymer and pore former polymer, respectively. The blends were carbonized at 800 °C in nitrogen. SEM, BET measurement and BJH method reveal that the obtained carbon possesses a mesoporous characteristic, with the average pore size between 3.0 nm and 5.0 nm. The electrochemical properties of supercapacitor using these carbons as electrode material were investigated by cyclic voltammetry and constant current charge-discharge. The results indicate that the composition of blended polymers has a strong effect on the specific capacitance. When the mass ratio of PF to gelatin is kept at 1:1, the largest surface area of 222 m²/g is obtained, and the specific capacitance reaches 161 F/g.     

Preparation and electrochemical characterization of activated carbons by chemical-physical activation

A process was proposed based on the combination of chemical and physical activation for the production of activated carbons used as the electrode material for electric double layer capacitor (EDLC). By material characterization and electrochemical methods, the influences of the activitation process on the specific surface area, pore structure and electrochemical properties of the activated carbons were investigated. The results show that specific surface area, the mesopore volume, and the specific capacitance increase with the increase of the mass ratio of KOH to char (m(KOH)/m(char)) and the activation time, respectively. When m(KOH)/m(char) is 4.0, the specific surface area and the mesopore volume reach the maximum values, i.e. 1 960 m²/g and 0.308 4 cm³/g, and the specific capacitance is 120.7 F/g synchronously. Compared with the chemical activation, the activated carbons prepared by chemical-physical activation show a larger mesopore volume, a higher ratio of mesopore and a larger specific capacitance. Foundation item: Project(2007BAE12B01) supported by the National Key Technology Research and Development Program of China     

Preparation and electrochemical characterization of C/PANI composite electrode materials

1 INTRODUCTIONRecently , surpercapacitor has attracted greatattention for its unique power performance[1 ,2],while electrode materials ,as one key factor to de-termine the performance of supercapacitor , nowbecome the focus of many researches . The super-capacitor materials can be categorized into threetypes :carbon electrode materials[3], metal oxide e-lectrode materials[4]and conductive polymer elec-trode materials[5].Conductive polymer electrode materials havehigher capacitance than tha…