超级电容器用马尾藻基超级活性炭的制备及其电化学性能

以马尾藻为原料,采用KOH活化法制备用于超级电容器的生物质基超级活性炭。制备的超级活性炭不仅比表面积巨大,孔隙结构丰富,而且以海藻作为前驱体原料明显降低了活性炭的生产成本。采用单因素实验法分析了浸渍比、活化温度和活化时间对马尾藻基活性炭孔隙结构(比表面积、孔容及孔径分布等)的影响,探索了制备马尾藻基超级活性炭的最佳工艺条件,并研究了所制活性炭用于制备超级电容器时的电化学性能。采用N2吸附-解吸附、SEM、XRD,恒电流充放电以及循环伏安法等表征手段考察超级活性炭样品的比表面积,孔结构以及电化学性能。实验结果表明,制备马尾藻基超级活性炭的最佳工艺条件为:浸渍比4∶1,活化时间120min,活化温度800℃。在该实验条件下制得的活性炭比表面积高达2926m2/g,孔容高达1.536cm3/g,且所有活性炭的孔径大小几乎全部分布在4nm以内,孔径分布均匀。制备的超级电容器以6mol/L的KOH为电解液时,其比电容高达358.5F/g,表现出良好的电化学性能。     

微波法煤基活性炭的制备及其电化学性能研究

以内蒙古优质褐煤为原料,KOH为活化剂,采用微波加热活化法制备超级电容器用活性炭,利用低温氮气吸附及恒流充放电、循环伏安等方法测定活性炭的孔结构及其用作电极材料的电化学性能,并与日本商业化超级电容器用活性炭在结构及性能方面进行对比分析。结果表明,在碱炭比为3,微波活化时间为20min的条件下,可制备出比表面积达2593m2/g、总孔容达1.685cm3/g、孔径主要分布在0.5～10nm之间、中孔率达67.3%、平均孔径为2.61nm的优质活性炭。该活性炭用作超级电容器电极材料在3mol/L KOH电解液中具有优异的电化学性能,电流密度由50mA/g提高到10A/g时,其比电容由346F/g降低到273F/g,显示出良好的功率特性,经1000次循环后,比电容保持率为93.2%。与商业活性炭相比,微波法活性炭的性能更加优良。     

利用核桃壳制备高比表面积活性炭电极材料的研究

以核桃壳为原料,采用KOH活化法制备活性炭,并将其用作超级电容器电极材料。利用N2吸附和扫描电镜(SEM)表征活性炭的孔结构及表面形貌,系统研究碱炭比(KOH与核桃壳炭化料的质量比)对活性炭孔结构的影响,并采用恒流充放电及循环伏安等测定核桃壳活性炭电极材料在3mol/L KOH电解液中的电化学性能。结果表明,随着碱炭比的增大,活性炭的比表面积、总孔容及中孔比例先逐渐增大后稍有减小。当活化温度为800℃,活化时间为1h,碱炭比为4时,可制备出比表面积为2404m2/g,总孔容为1.344cm3/g,中孔比例为28.6%,孔径分布在0.7~3.0nm之间的高比表面积活性炭。该活性炭用作超级电容器电极材料具有良好的大电流放电特性和优异的循环性能,电流密度由50mA/g提高到5000mA/g时,其比电容由340F/g降低到288F/g,经1000次循环后,比电容保持率为93.4%。     

双电层电容器用煤基活性炭的制备与电化学性能表征

以河南永城无烟煤为原料、KOH为活化剂制备了高比表面积的煤基活性炭,采用低温N_2吸附法对活性炭的比表面积、孔容及孔径分布进行了表征,并对其用作双电层电容器电极材料的电化学性能进行了系统测试.在KOH与煤的质量比为4:1、活化温度为800℃、活化时间为1h的条件下制备出的活性炭其比表面积高达3224m~2/g,总孔容达1.76cm~3/g,中孔率为57.95%.该活性炭电极在3mol/L KOH电解液中的比电容高达324F/g,且具有良好的循环性能,当电流密度为40mA/g时,经1000次循环后,比电容保持率超过92%,且其漏电流很小.     

炭化温度对酚醛树脂基活性炭孔结构及电化学性能的影响研究

以酚醛树脂为炭前驱体,KOH作活化剂,通过调节炭化温度在相同活化条件下制备了具有不同孔隙结构的活性炭材料.N_2吸附测试表明随着炭化温度降低,活性炭材料比表面积先增大后减小,孔容则不断增大.其中,550℃炭化样品与KOH反应活性最佳,可制得比表面积为2983m~2/g,总孔容为1.58cm~3/g,中孔孔容达到0.59cm~3/g的活性炭材料.采用直流充放电法、交流阻抗法和循环伏安法测定以上述多孔炭为电极材料的双电层电容器的电化学性能,结果表明,PF550活性炭材料电容性能最佳,在有机电解液中100mA/g充放电时,比电容达到160F/g,电流密度增大50倍容量保持率达到82%,显示出良好的功率特性;活性炭材料中存在一定比例的中孔不仅可以改善电极材料的功率特性,而且可以提高微孔的利用率.     

废茶叶基活性炭的制备及其电化学性能研究

以废茶叶的炭化料为前驱体,KOH为活化剂(碱炭比1∶1、2∶1、3∶1),在800℃下活化1h制备双电层电容器用活性炭电极材料。利用扫描电镜、低温N2吸附对活性炭的形貌、孔结构进行表征,采用恒流充放电、循环伏安和交流阻抗等测试方法评价其在3mol/L KOH电解液中的电化学性能。结果表明,3种活性炭比表面积、总孔容和中孔率最高分别达1 900m2/g、0.919 4cm3/g和35.7%;3种活性炭电极材料在0.055 6 A/g电流密度下的比电容分别为202F/g、255F/g、194F/g,电流密度增加到2.780A/g时,电容保持率分别为84.2%、67.1%、86.6%;等效串联电阻仅为0.10~0.12Ω;在碱碳比为2∶1时制备的活性炭电极材料在2.363A/g下比电容为148F/g,经1 000次循环充放电后,其质量比电容为147.7F/g,电容保持率高达99.3%。     

超级电容器用沥青焦基活性炭的制备及其电化学性能

采用沥青焦为原料，制备了系列高比表面积活性炭作为超级电容器电极材料。用直流循环充放电、循环伏安及交流阻抗等表征方法比较了沥青焦基超级活性炭和日本可乐丽公司YPl5活性炭的电化学性能。实验结果表明在KOH、H2SO4、（C2H5）4NBF4／碳酸丙烯酯（Propylenecarbonate PC）及（C2H5）4NBF4／乙腈（Acetonitrile）体系中，沥青焦基活性炭的比电容随比表面积增加，其最高值分别为257F／g、228F／g、140F／g、142F／g，均超过了日本活性炭。沥青焦基活性炭电极在KOH体系中的等效串联电阻的体积电阻率与日本炭相差不大；在H2SO4体系中的电阻率均小于日本活性炭；在碳酸丙烯酯体系中的电阻率均大于日本活性炭；在乙腈体系中，活化剂KOH与沥青焦比例为4：l、经800℃活化3h制备的活性炭的电阻率小于日本活性炭。     

孔结构对煤基活性炭电极材料电化学性能的影响(英文)

以太西无烟煤为前驱体,NaOH为活化剂制备电化学电容器电极材料。采用N2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。在1mol/L(C2H5)4NBF4/碳酸丙烯酯有机电解液体系中,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:以NaOH为活化剂可制备出比表面积943mol/L～2479mol/L、比电容57F/g～167F/g的活性炭电极材料。活性炭电极材料的比电容不仅取决比表面积,而且与活性炭的孔径分布有关。孔径为2nm～3nm的中孔的存在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,从而使电容器的电化学性能得到增强。     

高比表面积活性炭基水系Na_2SO_4电化学电容器的制备

以石油焦为前驱体和KOH作为活化剂制备一种用于电化学电容器的高比表面积活性炭,采用廉价弱腐蚀性的Na_2SO_4电解液制备一种高电压的对称活性炭基水系电化学电容器,用N2吸附-脱附仪表征活性炭电极材料的孔结构参数,用循环伏安、恒流充放电和交流阻抗等电化学测试方法研究其电化学性能。研究结果表明,活性炭的比表面积为2855m~2/g,平均孔径为2.31nm;活性炭基水系电化学电容器在1.0mol/L Na_2SO_4电解液中扫描速率为2mV/s的比电容能达到188F/g,在功率密度为200W/kg时能量密度达到19.4Wh/kg,活性炭基水系电化学电容器在电压值为1.6V下展现了良好的循环性能,意味着Na_2SO_4电解液对开发能量密度高和环境友好的电化学电容器有着重要的意义。     

针状焦基活性炭的制备及其作为EDLCs电极材料的电化学性能

以针状焦生焦为原料,通过KOH化学活化法,在不同活化条件下制备出一系列高比表面积活性炭,并对这些活性炭进行了孔结构表征.而后以30 % KOH溶液为电解液,测试了由所获活性炭制备的一系列电极的电双层电容性能.结果表明：在碱炭比7：1、活化温度850 ℃时,所制活性炭的BET比表面积为2 728 m^2/g,孔容为2.14 cm^3/g,统计平均孔径为4.4 nm,大中孔孔容占总孔孔容约50 %.该活性炭电极的比电容达305 F/g,有相对较高的能量密度、良好的功率特性以及双电层电容特性.     

预炭化对KOH活化石油焦的结构及电容性能的影响

以不同温度炭化的石油焦为原料、KOH为活化剂制备电化学电容器用炭电极材料. 采用XRD、TEM和N₂吸附法对前驱体及活化产物的结构进行了表征, 并考察了样品的电化学性能. 结果表明: 通过调整前驱体的预炭化温度, 可实现对石油焦基活性炭的微晶结构和孔结构的调控, 分别制得无晶体特性的高比表面积活性炭和由大量类石墨微晶构成的低比表面积活性炭. 低表面积活性炭依靠充电过程中电解质离子嵌入类石墨微晶层间而实现能量存储, 具有比高比面积活性炭高10倍的面积比电容和更大的体积比电容.     

Physical and chemical properties and adsorption type of activated carbon prepared from plum kernels by NaOH activation

Activated carbon was prepared from plum kernels by NaOH activation at six different NaOH/char ratios. The physical properties including the BET surface area, the total pore volume, the micropore ratio, the pore diameter, the burn-off, and the scanning electron microscope (SEM) observation as well as the chemical properties, namely elemental analysis and temperature programmed desorption (TPD), were measured. The results revealed a two-stage activation process: stage 1 activated carbons were obtained at NaOH/char ratios of 0-1, surface pyrolysis being the main reaction; stage 2 activated carbons were obtained at NaOH/char ratios of 2-4, etching and swelling being the main reactions. The physical properties of stage 2 activated carbons were similar, and specific area was from 1478 to 1887m(2)g(-1). The results of reaction mechanism of NaOH activation revealed that it was apparently because of the loss ratio of elements C, H, and O in the activated carbon, and the variations in the surface functional groups and the physical properties. The adsorption of the above activated carbons on phenol and three kinds of dyes (MB, BB1, and AB74) were used for an isotherm equilibrium adsorption study. The data fitted the Langmuir isotherm equation. Various kinds of adsorbents showed different adsorption types; separation factor (R(L)) was used to determine the level of favorability of the adsorption type. In this work, activated carbons prepared by NaOH activation were evaluated in terms of their physical properties, chemical properties, and adsorption type; and activated carbon PKN2 was found to have most application potential.     

氢氧化钾／石油焦质量配比对活性炭性能的影响

本文以石油焦为原料，采用氢氧化钾化学活化法系统考察了氢氧化钾／焦炭的质量配比（碱／炭，Ｗｂ／Ｗｃ）对活性炭吸附性能和孔隙性能的影响。结果表明，随着碱／炭比的增加，吸附性能显著提高；比表面积，总孔容积，微孔容积和非微孔容积都增加；孔径分布变窄，平均孔径减少。碱／炭比大于等于３∶１时，所得活性炭试样的比表面积大于３０００ｍ２／ｇ。     

原料粒度对石油焦基活性炭性能的影响

以不同粒度范围的石油焦为原料,KOH为活化剂,采用化学活化工艺制备了超级电容器用活性炭电极材料.采用N2吸附法表征了活性炭材料的BET比表面积及孔结构;在1mol/L的Et4NBF4/AN有机电解液体系下组装成模拟电容器,并考察了活性炭材料的电化学性能.结果表明:随着原料粒度的减小,活性炭的振实密度和收率先增大,然后再减小.原料粒度范围越窄,活性炭具有越小的BET比表面积和孔容.在1mol/L的Et4NBF4/AN电解液体系下,随着石油焦粒度的不断减小,活性炭材料的质量比容量不断增大,在粒度<38μm时取得最大值140F/g.粒度为38～44μm的石油焦制备出的活性炭在1A/g电流下质量比容量为126.6F/g,在20A/g电流下质量比容量为116.2F/g,容量衰减只有8.2%,表现出良好的功率特性.     

Characterization and use of high surface area activated carbons prepared from cane pith for liquid-phase adsorption

Carbonaceous adsorbents with controllable surface areas were chemically activated with KOH at 780 degrees C from char that had been carbonized from cane pith at 450 degrees C. The pore properties including the BET surface area, pore volume, pore size distribution, and mean pore diameter of these activated carbons were characterized and derived using the t-plot method based on N(2) adsorption isotherms. The activated cane pith carbons, with KOH/char ratios of 2-6, exhibited BET surface areas ranging from 912 to 2299 m(2) g(-1). The scanning electron microscopic (SEM) observations revealed that the surface morphology of honeycombed holes on all activated cane pith carbons was significantly influenced by the KOH/char ratio. The adsorption kinetics and equilibrium isotherms of acid blue 74, methylene blue, basic brown 1, p-nitrophenol, p-chlorophenol, p-cresol, and phenol from water at 30 degrees C on the activated carbons were studied. The adsorption kinetics were suitably described by a simplified kinetic model, the Elovich equation. All adsorption equilibrium isotherms were in agreement with the Langmuir equation, and were used to compare the covered area (S(c)/S(p)) of the activated carbons at different KOH/char ratios. The high-surface-area activated carbons were proven to be promising adsorbents for pollution control and for other applications.     

不同结构活性炭对甲苯的吸附性能

考察了不同结构的活性炭样品对高浓度和低浓度甲苯蒸汽的吸附行为,采用低温(77 K)氮气吸附和129Xe-核磁共振方法对所用活性炭的结构进行了表征.并将活性炭对甲苯的吸附性能与其结构进行了关联.结果表明孔容积大的活性炭对高浓度甲苯蒸汽吸附容量大,而具有丰富微孔和较小平均孔径的活性炭对低浓度(2×10-5)甲苯蒸汽具有高的吸附容量.沥青基活性炭纤维对低浓度(2×10-5)甲苯蒸汽表现出较好的吸附能力.随着比表面积的增大,活性炭纤维对低浓度(2×10-5)甲苯蒸汽的吸附容量略有增加.OG5A,OG10A,OG15A和OG20A在30 ℃下对2×10-5甲苯蒸汽的饱和吸附容量分别为202 mg/g,219 mg/g,221 mg/g和235 mg/g.     

表面改性对活性炭孔结构及热电转换性能的影响

为探究表面改性对活性炭孔结构及热电转换性能的影响,使用HNO_3和KOH在不同条件下对活性炭进行表面改性,用N2吸附法和XRD图谱表征活性炭改性前后孔结构和石墨化程度的变化。结果表明,改性后活性炭的比表面积和孔容提高,平均孔径减小,并存在石墨晶体结构。干法改性活性炭的比表面积和总孔容由1 077.880m~2/g和0.763cm~3/g分别增加到1 635.268m~2/g和1.128cm~3/g,并且微孔的孔容增加。改性处理可以去除活性炭中的杂质。分别以改性前后活性炭为材料制备固体电极,KCl为电解液,测试活性炭电极的热电转换性能,发现改性后活性炭具有更高的热电转换性能。     

Kinetics of degradation of sulphur mustard on impregnated carbons

Kinetics of degradation of sulphur mustard (HD) on the surface of NaOH/CrO3/C, NaOH/CrO3/EDA/C and RuCl3/C systems has been examined by using gas chromatography technique by extracting and analyzing the residual HD periodically. The carbons were prepared by impregnating activated carbon with 4% sodium hydroxide plus 3% Cr(VI) as CrO3 with and without 5% ethylene diamine (EDA) and 5% ruthenium chloride by using their aqueous solutions. Obtained carbons were characterized for surface area analysis by BET conventional method. Kinetic plots reveal that the observed reactions are fast at the initial stages, slow at the later stages and progress to a steady state indicating the first order behavior. Effect of moisture on kinetic rate is also observed. In the case of NaOH/CrO3/C system the rate constant is decreased from 13.36 to 5.53 x 10(-2) h(-1) and half life is increased from 5.2 to 12.54 h while moisture content is increased from 1.9% to 11.2%. Whereas, the rate constant of HD degradation reaction is decreased from 10.4 to 4.14 x 10(-2) h(-1) and half life is increased from 6.7 to 16.72 h while moisture content is increased from 2.1% to 10.8% on NaOH/CrO3/EDA/C. Reaction on RuCl3/C system also behaves in the similar manner. Extracted reaction products were characterized by GC/MS and it is found that on NaOH/CrO3/C, HD degrades to hemisulphur mustard, thiodiglycol and 1,4-oxathiane. Whereas, on NaOH/CrO3/EDA/C, HD is degraded to 1,4-thiazane and it is degraded to divinyl sulphone on RuCl3/C. All these investigations reveal that above mentioned carbons can be used in nuclear, biological and chemical (NBC) filtration systems for protection against sulphur mustard.     

石油焦预氧化对超级活性炭孔结构和表面性质的影响

以石油焦为原料，KOH为活化剂合成了高比表面积超级活性炭。采用扫描电镜（SEM）和氮气低温静态吸附技术对超级活性炭样品的结构和性质进行了表征。同时，通过反应快速终止技术和原位TG－DTA实验侧重考察了石油焦预氧化对超级活性炭孔结构和表面性质的影响。实验表明：石油焦预氧化能够显著改变活化反应的进程和抑制高温恒温段中大孔的形成。红外测试亦显示石油焦预氧化能够促进活化过程中稠环芳香结构的解体和活性炭表面含氧物种的生成。