CN109637843A - 一种以芹菜为电极原料制备超级电容器的方法 - Google Patents
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Abstract
本发明属于超级电容器制备领域,具体为一种以芹菜为原料制备超级电容器电极的方法。本发明首先把芹菜茎用去离子水洗干净,然后将其放在真空冷冻干燥机中冻干,随后将干燥后的芹菜在惰性保护气中高温碳化,以所得石墨化多孔碳为电极,在其中填充凝胶电解质并在两个电极中间涂覆凝胶电解质进而组装得到超级电容器。该方法利用低成本的生物质材料芹菜为原料,为充分发挥其生物细胞结构优势,首先通过冷冻干燥保护其原有结构,再通过碳化制备具有多级孔径分布的石墨化多孔碳材料,将其用于超级电容器电极,实现了超级电容器电极原材料的可循环再生、低成本化,其制备工艺简便,且所得超级电容器性能优良,具有良好的应用前景。
Description
技术领域
本发明属于超级电容器制备领域,特别涉及一种以芹菜为原料制备超级电容器电极的方法。
背景技术
超级电容器因其大容量、高功率密度和良好的循环稳定性而在储能领域占有不可替代的地位。然而,超级电容器的性能主要取决于它们的电极材料是否具有大的比表面积、高的导电性、良好的稳定性和强的反应活性。目前,大多数研究采用金属化合物(如RuO2,Fe3O4或MoS2)[1-2]、导电聚合物[3]、碳纳米材料(如碳纳米管[4],石墨烯[5],多孔碳[6])及其复合物[7]作为电极材料,其原料通常不可再生,制备工艺复杂,成本较高。
生物质具有成本低、环保、可再生的优点,且含有大量的水分和养料输送通道,因此可用作多孔碳的前驱体[8]。目前已有一些使用生物质作为前驱体制备电极材料的研究,他们通常是直接将其高温碳化[9],这不可避免地会导致生物质组成成分的流失和部分原始结构的破坏,无法充分发挥生物质的组成和结构优势。 Sun、Liu等通过一步热解柚子皮获得蜂窝状硬碳,将其用于钠离子电池,电流密度在30mA/g时的比容量为430.5mAh/g,且充放电200次后容量损失仅为5%,储能性能优越,但其电极比表面积仅为82.8m2/g,还有很大提升空间[10]。为了提高电极的导电性和比容量,一些科研工作者致力于对所得碳材料进行活化和氮掺杂等方面的研究[11-12]。其中,活化是提高材料比表面积进而提高其比容量的一种有效方法,例如,Thomas E.Rufford等利用ZnCl2对咖啡渣进行活化,比表面积有所提高,但所使用活化剂ZnCl2具有腐蚀性和毒性,不够环保[11b],亟待发展更为环保、高效的方法实现高性能电极材料的制备。
本发明提出首先采用冷冻干燥技术保护生物质原始组成和结构,再通过高温碳化技术制备石墨化多孔碳纳米材料,从而使生物质的优势得到充分保留和发挥。冷冻干燥起源于生物医学领域,冻干过程中的热损失低于其他干燥方法,且所得材料具有高孔隙率,近年来已被用于制备多孔材料,如多孔陶瓷[13],气凝胶[14],石墨烯[15]等,取得了良好的效果。
然而到目前为止,国内外尚未见以生物质为原料,通过真空冷冻干燥结合碳化方法,而未采取其他活化、掺杂等复杂方法,即可得到如此性能优良的超级电容器电极材料的报道。
发明内容
本发明针对现有技术中存在的缺陷或不足,创新性地提出了一种以芹菜为原料制备超级电容器电极的方法,该制备方法中原料可再生、制备工艺简单、成本低、无污染、可规模化生产。
本发明以纤维化程度高、元素组成多样、细胞组成中水分含量高、且含有大量水分和养分输送通道的芹菜为原料,首先经过真空冷冻干燥技术保护其原有细胞壁骨架结构不坍塌,再通过高温碳化制备比表面积大、具有多级孔径分布的多孔碳材料,将所得多孔碳材料与导电剂乙炔黑及粘结剂PTFE混合均匀涂在不锈钢网集流体上,真空干燥后得到电极,然后在其中填充聚乙烯醇/磷酸凝胶电解质,并在两个相同电极中间均匀涂布一层聚乙烯醇/磷酸凝胶状电解质进而组装得到超级电容器。
本发明提供的以芹菜为原料制备超级电容器电极的方法,具体包括以下步骤:
(1)将芹菜用去离子水洗干净,切成小条;
(2)用液氮将小条状的芹菜快速冻结;
(3)将冻住的芹菜放在真空冷冻干燥机里在冷阱温度为-40~-60℃,压强为1~10Pa的条件下冻干24~72h,室温前期为5~15℃,后期为25~30℃,最后4h用红外灯照射样品,使样品温度达到30~35℃,样品冻干后使干燥机内气压还原至大气压,取出样品;
(4)将冻干后的芹菜放在管式炉中,在Ar(20~1000sccm)的保护气氛中,炉子按2~15℃/min的升温速率加热至600~1000℃,恒温0.2~5h,待炉温冷却至室温后将样品取出,即得多级孔径分布的石墨化多孔碳材料;
(5)将所制备的多孔碳材料用玛瑙研钵研成粉末,然后按质量比为多孔碳: 乙炔黑:聚四氟乙烯(PTFE)粘结剂=16:3:1的比例将其在研钵中混合研磨均匀后涂于不锈钢网集流体上,从而得到超级电容器电极;
(6)在1mol/L的H2SO4水溶液中,以所得石墨化多孔碳材料为工作电极、Ag/AgCl为参比电极、Pt丝为对电极构成三电极体系,对所得石墨化多孔碳材料进行电化学性能测试;
(7)将两个相同的由步骤(1)-(5)所得的石墨化多孔碳材料电极内部填充聚乙烯醇/磷酸凝胶状电解质,并在两电极中间均匀涂布一层聚乙烯醇/磷酸凝胶状电解质,组装得到超级电容器。
本发明的冷冻干燥过程中,冷冻干燥时间为24~100h,环境温度为5~35℃,第一阶段为升华阶段,冰大量升华,此时样品的温度不宜低于最低共熔点,以防样品中产生僵块或样品外观上的缺损,故在前20h环境温度通常控制在 5~15℃;后24h为样品的再干燥阶段,此时所除去的水分为结合水分,如果不对样品进行加热或热量不足,则在水分升华时会吸收样品本身的热量而使样品的温度降低,致使样品的蒸气压降低,引起升华速度的降低,整个干燥的时间就会延长,生产率下降;如果对样品加热过多,样品的升华速率固然会提高,但在抵消了样品升华所吸收的热量之后,多余的热量会使冻结样品本身的温度上升,使样品可能出现局部甚至全部熔化,引起样品的干缩起泡现象,整个冷冻干燥过程就会失败,故在保证样品质量的前提下,在此阶段内应适当提高环境温度至 25~30℃,以利于水分的蒸发;在最后4h将环境温度升高至30~35℃进一步加速结合水的升华并加深冻干效果,直至样品温度与环境温度重合达到干燥为止。因此本发明发现,48h为最佳冻干时间。
本发明的碳化过程中,碳化温度为600~1000℃,碳化时间为0.2~5h,随着碳化温度或碳化时间的增加,石墨化程度增强,电极材料的导电性和稳定性也随之增强,但部分孔结构被破坏程度加深,比表面积减小,比容量下降。综合考虑各方面因素,本发明发现,800℃为最佳碳化温度,1h为最佳碳化时间。
本发明所制备的超级电容器中,冷冻干燥后的芹菜在800℃碳化1h后得到的多孔碳材料的比容量在1A/g时,可达到300F/g,能量密度和功率密度分别可达26.6Wh/kg和0.801kW/kg,值得一提的是,在20A/g的电流密度下,能量密度和功率密度分别可以达到16.3Wh/kg和16.0kW/kg,是商用碳基超级电容器 (功率密度为7~8kW/kg)的两倍[16]。
本发明采用扫描电子显微镜(SEM),透射电子显微镜(TEM)和氮气吸脱附测试清楚地表征了由芹菜制备的多孔碳材料的结构独特性。图1(a,b和c) 展示了多孔碳的场发射扫描电子显微镜(SEM)照片。如图1a所示,在碳化温度为700℃时,样品中没有三维互相连通的孔,这种现象应该归因于碳化温度太低,无法形成许多纳米级的孔;当碳化温度升高为800℃时,如图1b所示,样品中含有大量大小不一、互相连通的孔;然而,进一步将碳化温度升高为 900℃时,如图1c所示,碳材料中的一些小孔被破坏而形成大的网络。进一步用透射电子显微镜(TEM)表征碳化温度为800℃的样品,如图1d所示,可以看出样品中有大量的微孔和介孔。
多孔碳材料的氮气吸脱附等温线如图2a所示,不同碳化温度下所得样品的Brunauer-Emmett-Teller(BET)比表面积为155~1700m2/g。对于碳化温度为 800℃的样品,其比表面积为523m2/g,总孔容为0.639cm3/g,微孔体积为0.039 cm3/g,平均孔径为3.32nm。使用非局部密度泛函理论(DFT)得到的孔径分布在图2b中给出,可以看出该样品的孔结构主要为微孔和介孔,比表面积较大,且有利于离子在充放电时的嵌入与脱出。
本发明还通过粉末X射线衍射(XRD)法对石墨化多孔碳材料的结构进行了表征。如图3a所示,在多孔碳材料的XRD图中观察到以2θ=24.3°为中心的宽衍射峰,通过谢乐公式可以计算层间距为0.366nm,其代表石墨烯的(002)晶面间距,另外,还可以观察到位于2θ=42.3°的峰,对应d(100)≈0.213nm。可以看出所得石墨化多孔碳中的层间隙都大于H+的直径(dH +≈0.056nm),因此有利于 H+的嵌入和脱出[17]。
本发明采用拉曼光谱分析进一步研究了三维多级孔径分布的多孔碳结构,结果如图3b所示。无序石墨(sp2)的拉曼光谱显示出两种非常尖锐的模式,D波段约为1358cm-1,G波段约为1583cm-1。另一方面,2418cm-1附近的宽带属于 G*带,说明材料中存在少数层石墨烯叠加结构[18]。此外,在1096cm-1处有一个C(芳香族)-S峰,表明该材料制备过程中有效地保护了原料中的硫元素,所得石墨化多孔碳中存在硫掺杂结构,该结构在石墨化结构中可以作为结构缺陷有效增加储能活性位点[19]。另外,对不同碳化温度下所得的样品进行石墨化程度表征,可以得到ID/IG(700)<ID/IG(800)<ID/IG(900),表明随着温度的升高,石墨化程度也随之增加。
如前所述,生物质中含有除碳元素外的多种掺杂元素,为研究制备过程中掺杂元素的保留情况,本发明进一步用元素分析表征了所得石墨化多孔碳的元素组成。结果表明,样品中含有一些杂元素(N,S,P等),同时含有一定量的氧元素,与碳和氢反应产生的气体CO2和H2O蒸气可以进一步活化样品,使样品产生更多的孔隙(表1)。
为得到具有良好储能性能的超级电容器电极,本发明探索了不同碳化温度对所得石墨化多孔碳电极材料储能性能的影响。图4a为不同碳化温度所得石墨化多孔碳电极在10mV/s扫速下的循环伏安曲线。可以看出,随着碳化温度由 700℃升高至900℃的过程中,循环伏安曲线越来越接近矩形,电极极化现象减弱,这是由于随着碳化温度的升高,生物质中的含氧基团分解更彻底,且石墨化程度增加所致,与图3b分析结果一致。另外,从该循环伏安图还可以看出,同样在10mV/s的扫速下,800℃对应曲线包围的面积最大,初步推断在一定电流密度范围内800℃的样品比容量比较高,这是由于碳化温度从700℃升高至 800℃过程中,部分含氧基团被分解可以在原有结构上形成一部分新孔,从而有效提高材料的比表面积,同时石墨化程度增加,有利于其储能性能的充分发挥;但当碳化温度进一步升高至900℃,温度过高导致生物质中含氧基团被分解的同时大量含有N,S,O元素的化合物也被分解,且其有效孔结构遭到一定程度的破坏,介孔扩大形成大孔网络,同时在其生物质细胞壁上形成新的极小的微孔,虽对比表面积有所贡献,但无法储存电荷,故其储能有效比表面积降低,从而使其比容量降低。
本发明对不同碳化温度下所得的石墨化多孔碳在1A/g的电流密度下进行了恒流充放电测试,测试曲线如图4b所示。由该图计算可得,碳化温度由700℃增加为800℃时,放电比容量由280F/g增加为350F/g,而当碳化温度进一步从800℃增加为900℃时,其比容量反而从350F/g降低为168F/g,与以上循环伏安测试分析的结果一致,有效证明了随碳化温度的升高,有机基团逐步分解,石墨化程度增加,但当温度太高时,有效孔结构会遭到一定破坏,且一些掺杂元素也被分解。
为系统表征不同碳化温度的样品的倍率性能,本发明对各温度所得石墨化多孔碳电极在1、2、5、10、20A/g下分别进行了恒流充放电测试,如图4c所示,可以看出,在1A/g的电流密度下进行恒流充放电,800℃所得样品的比容量明显高于700℃和900℃,随着电流密度逐渐增大为20A/g,700℃的样品比容量降低最为明显,降为140F/g,800℃的降低为184F/g,而900℃的样品随着电流密度由1A/g增加至20A/g,比容量仅仅从168F/g降低至120F/g,倍率性能最稳定,进一步说明随着碳化温度的升高,石墨化程度增加,高倍率性能得到优化。为进一步表征石墨化多孔碳电极的储能机制,本发明在0.01~100000Hz 的频率范围内对电极进行了电化学阻抗谱(EIS)测试。如图4d所示,低频区域的直线几乎垂直于横坐标轴,这表明电极主要以电容器的形式存储能量。同时从横轴截距可以看出,随着温度的升高,电极的内阻减小,进一步说明电极的导电性增强,即石墨化程度提高,故选择800℃为最佳碳化温度。
在优化碳化温度的基础上,本发明还进一步考察了不同碳化时间对电极比容量的影响(如图5所示)。由图5a可以看出,随着碳化时间由30min延长至120 min,所得石墨化多孔碳电极在10mV/s下的循环伏安曲线形状相似,均接近矩形,但碳化60min所得电极的曲线包围面积最大,说明其在一定充放电速率下的比容量最大。将不同碳化时间所得样品在1A/g电流密度下充放电得如图5b 所示曲线,可以明显看出碳化时间为60min所得样品的比容量最大,为350F/g, 30min和120min所得电极的比容量分别为221F/g和294F/g,这是由于当碳化时间为30min时,时间过短,导致生物质样品中含氧基团分解不完全,未形成大量的连通孔,故比容量较低,随着碳化时间延长至60min,含氧基团逐渐被分解,在原生物质细胞壁上产生大量连通孔,有效比表面积增加,比容量提升至 350F/g;而当碳化时间进一步延长至120min时,由于过长时间的碳化使有机质被过度分解,导致部分孔结构被破坏,故比容量下降。
同样,为进一步表征不同碳化时间所得石墨化多孔碳电极的倍率性能,本发明在1、2、5、10、20A/g的电流密度下对电极进行充放电,所得放电比容量如图5c所示,可以看出当电流密度在5A/g以上时,其不同碳化时间所得材料的比容量随电流密度增加而减小的程度近似,说明在同样的碳化温度下其主体孔结构的石墨化程度相近,但当电流密度低于5A/g时,尤其随着电流密度由1A/g 增加为2A/g,碳化30min比60min的样品比容量减少更小,进一步证明随着碳化时间延长,样品结构中含氧基团分解,在生物质细胞壁上形成一部分较小的连通孔扩大了比表面积,但由于孔较小,当电流密度较大时,电解液中的离子无法快速扩散进入该孔,导致只有电流密度较小时才可以有效提高比容量;然而,120 min所得样品随着电流密度由1A/g增加至5A/g比容量减小最为剧烈,这是由于当碳化时间过长时,不仅原有孔结构遭到破坏,同时也形成了新的更小的孔,故在较小的电流密度1A/g下,新形成的较小的孔在比容量中的贡献比例更大,故随着电流密度的增加,比容量下降更为明显。进一步对其进行电化学阻抗谱 (EIS)测试,如图5d所示,低频区域的直线与横坐标轴接近垂直,这表明电极主要以电容器的形式存储能量。基于以上结论,本发明选择60min为最佳碳化时间。
综合以上数据,本发明选取碳化温度800℃、碳化时间60min作为制备石墨化多孔碳电极材料的主要实验参数,对所得样品在扫描速率为10、20、50和 100mV/s时分别进行了循环伏安测试,如图6a所示,所得循环伏安图均为矩形形状,说明电极材料以双电层电容储能为主。如图6b所示,电流密度范围为1~20 A/g的恒电流充放电测试,所有曲线均为对称三角形,进一步证明电极主要通过双电层电容存储能量。由恒流充放电测试结果计算得该样品在1A/g下的放电比容量为350F/g,将电流密度增加至20A/g时,容量仍可达到184F/g,进一步计算其能量密度和功率密度,该样品在功率密度为0.4kW/kg时,能量密度可达31.1Wh/kg。
本发明在以上三电极体系中测试所得石墨化多孔碳电极电化学性能的基础上,通过在电极中填充聚乙烯醇/磷酸凝胶电解质制备全固态电极,并在两个电极间涂覆凝胶电解质组装得到全固态对称超级电容器。如图7所示为所得超级电容器的电化学储能测试结果,在图7a所示的循环伏安图中,当扫描速率由10 mV/s增加至100mV/s时,循环伏安曲线保持典型的矩形形状,这表明该超级电容器以双电层电容储能为主,且超级电容器高倍率性能良好,内部电阻较低。对其进行恒电流充放电测试,如图7b所示,当电流密度从1A/g增加至20A/g时,充放电曲线的对称三角形形状可以得到良好的保持,进一步说明其以双电层电容储能为主,且倍率性能良好,经计算得电流密度为1A/g时,电极的比容量为299 F/g,能量密度为26.6Wh/kg,相应的功率密度为0.801kW/kg。值得一提的是,在20A/g的电流密度下,功率密度高达16.0kW/kg,同时其能量密度保持在16.3 Wh/kg,高于商用碳基超级电容器(功率密度为7~8kW/kg)[16]。进一步对其进行交流阻抗谱测试,如图7c所示,在高频范围内没有明显的半圆,低频区域的直线接近垂直于横坐标轴,进一步表明该器件的电容储能机理。本发明还对该超级电容器在电流密度为10A/g下进行长效循环性能测试,如图7d所示,在10 万次循环后,比容量仍能保持60.6%。
综上所述,本发明发展了一种以芹菜为原料,通过冷冻干燥法和高温碳化法制备高性能超级电容器电极的方法。该方法采用具有低成本、环保、可再生等优势的生物质为原料,并首先利用冷冻干燥法有效保护其生物细胞结构优势,再通过优化碳化温度和时间,制备出具有多级孔径分布的石墨化多孔碳材料,将其用于超级电容器电极,表现出优良的储能性能,在1A/g下比容量高达350F/g,且在功率密度高达16kW/kg的情况下,能量密度仍能达到16.3Wh/kg。由此,本发明制备了具有优良储能性能的超级电容器电极材料,并实现了超级电容器电极原材料的可循环再生、低成本化,其制备工艺简便,具有良好的应用前景。
图1为在(a)700℃,(b)800℃,(c)900℃碳化所得石墨化多孔碳材料的扫描电子显微镜照片,(d)为800℃碳化所得石墨化多孔碳材料的透射电镜照片。
图2为不同碳化温度下所得石墨化多孔材料的(a)N2吸脱附曲线图,(b)孔径分布曲线图。
图3为石墨化多孔碳材料的(a)的XRD图,(b)拉曼光谱图。
表1为石墨化多孔碳材料所含元素的种类及含量。
图4为不同碳化温度下所得石墨化多孔碳材料(a)在扫描速率为10mV/s时的循环伏安图,(b)在电流密度为1A/g时的恒电流充放电曲线,(c)不同电流密度下充放电的比容量变化图,(d)频率在0.01~100000Hz之间的电化学阻抗谱。
图5为不同碳化时间下所得石墨化多孔碳材料的(a)扫描速率为10mV/s时的循环伏安图,(b)电流密度为1A/g时的恒电流充放电曲线,(c)不同电流密度下的比容量变化图,(d)频率在0.01~100000Hz之间的电化学阻抗谱。
图6为800℃碳化所得石墨化多孔碳电极材料的(a)不同扫描速率下的循环伏安图,(b)不同电流密度下的恒电流充放电曲线。
图7为所得石墨化多孔碳材料制备的对称超级电容器的(a)不同扫描速率下的循环伏安曲线,(b)不同电流密度下的恒电流充放电曲线,(c)频率在0.01~100000 Hz之间超级电容器的电化学阻抗谱,(d)超级电容器器件在10A/g下的长效循环性能图,C0和C分别代表循环前后的比容量。
图8为摘要附图,是本发明内容的简要示意图。
具体实施方式
首先将芹菜用去离子水洗干净,切成小条;然后用液氮将小条状的芹菜快速冻结;再将冻住的芹菜放在真空冷冻干燥机里在冷阱温度为-40~-60℃,压强为 0.5~10Pa的条件下冻干24~72h,室温前期为5~15℃,后期为25~30℃,最后 4h用红外灯照射样品,使样品温度达到30~35℃,样品冻干后使干燥箱内气压还原至大气压,取出样品;随后将冻干后的芹菜放在管式炉中,在Ar(20~1000 sccm)的保护气氛中,炉子按2~15℃/min的升温速率加热至600~1000℃,恒温0.2~5h,待炉子冷却至室温后将样品取出,即得多级孔径分布的石墨化多孔碳材料;再将所制备的多孔碳材料用玛瑙研钵研成粉末,然后按多孔碳:乙炔黑: 聚四氟乙烯(PTFE)粘结剂=16:3:1的质量比将其在研钵中混合研磨均匀涂于不锈钢网集流体上,从而得到超级电容器电极;在1mol/L的H2SO4水溶液中,以所得石墨化多孔碳材料为工作电极、Ag/AgCl为参比电极、Pt丝为对电极构成三电极体系,对所得石墨化多孔碳材料电极进行超级电容器的电化学性能测试;
包含PVA/H3PO4凝胶电解质的配制方法如下,先将1g PVA在9g去离子水中溶胀过夜,再加热至90℃,搅拌2h至溶解,冷却至室温后加入1g浓磷酸溶液(H3PO4质量分数为85wt%),搅拌均匀。将上面得到的电极内部填充聚乙烯醇/磷酸凝胶电解质,并在两个相同电极中间均匀涂布一层凝胶状电解质,组装得到超级电容器。
电极的电化学阻抗谱(EIS)测试在开路电压下进行,交流电振幅为5mV,频率范围为0.01~100000Hz。
参考文献
[1]Wu,N.L.,Nanocrystalline oxide supercapacitors.Materials Chemistry&Physics 2002,75(1),6-11.
[2]Acerce,M.;Voiry,D.;Chhowalla,M.,Metallic 1T phase MoS2nanosheetsas supercapacitor electrode materials.Nature Nanotechnology 2015,10(4),313-318.
[3]Rudge,A.;Davey,J.;Raistrick,I.;Gottesfeld,S.;Ferraris,J.P.,Conducting polymers as potential active materials in electrochemicalsupercapacitors.1992.
[4](a)Wang,G.;Liang,R.;Liu,L.;Zhong,B.,Improving the specificcapacitance of carbon nanotubes-based supercapacitors by combiningintroducing functional groups on carbon nanotubes with using redox-activeelectrolyte.Electrochimica Acta 2014, 115(3),183-188;(b)Bai,X.;Hu,X.;Zhou,S.;Yan,J.;Sun,C.;Chen,P.;Li,L.,In situ polymerization and characterization ofgrafted poly (3,4-ethylenedioxythiophene)/multiwalled carbon nanotubescomposite with high electrochemical performances.Electrochimica Acta 2013,87(1),394-400;(c)Paul, S.;Choi,K.S.;Dong,J.L.;Sudhagar,P.;Yong,S.K.,Factorsaffecting the performance of supercapacitors assembled with polypyrrole/multi-walled carbon nanotube composite electrodes.Electrochimica Acta 2012,78(9),649-655;(d)Yang, M.;Cheng,B.;Song,H.;Chen,X.,Preparation andelectrochemical performance of polyaniline-based carbon nanotubes aselectrode material for supercapacitor. Electrochimica Acta 2010,55(23),7021-7027.
[5](a)Chen,Y.;Zhang,X.;Zhang,D.;Yu,P.;Ma,Y.,High performancesupercapacitors based on reduced graphene oxide in aqueous and ionic liquidelectrolytes.Carbon 2011,49(2),573-580;(b)Zhang,L.;Shi,G.,Preparation ofHighly Conductive Graphene Hydrogels for Fabricating Supercapacitors withHigh Rate Capability.Journal of Physical Chemistry C 2011,115(34),17206-17212;(c) Jin,Y.;Huang,S.;Zhang,M.;Jia,M.;Hu,D.,A green and efficient methodto produce graphene for electrochemical capacitors from graphene oxide usingsodium carbonate as a reducing agent.Applied Surface Science 2013,268(3),541-546.
[6](a)Fuertes,A.B.;Lota,G.;Centeno,T.A.;Frackowiak,E.,Templatedmesoporous carbons for supercapacitor application.Electrochimica Acta 2005,50(14),2799-2805;(b)Xia,K.;Gao,Q.;Jiang,J.;Hu,J.,Hierarchical porous carbonswith controlled micropores and mesopores for supercapacitor electrodematerials. Carbon 2008,46(13),1718-1726.
[7](a)Sharma,R.K.;Rastogi,A.C.;Desu,S.B.,Manganese oxide embeddedpolypyrrole nanocomposites for electrochemical supercapacitor.ElectrochimicaActa 2008,53(26),7690-7695;(b)Khomenko,V.;Frackowiak,E.;Béguin,F.,Determination of the specific capacitance of conducting polymer/nanotubescomposite electrodes using different cell configurations.Electrochimica Acta2005, 50(12),2499-2506;(c)Zang,J.;Bao,S.J.;Li,C.M.;Bian,H.;Cui,X.;Bao,Q.;Sun,C.Q.;Guo,J.;Lian,K.,Well-Aligned Cone-Shaped Nanostructure of Polypyrrole/RuO2 and Its Electrochemical Supercapacitor.Journal of Physical Chemistry C2008,112(38),14843-14847;(d)Zhang,K.;Zhang,L.L.;Zhao,X.S.; Wu,J.,Graphene/polyaniline nanofiber composites as supercapacitor electrodes. Chemistry ofMaterials 2010,22(4),1392-1401;(e)Amade,R.;Jover,E.;Caglar,B.; Mutlu,T.;Bertran,E.,Optimization of MnO2/vertically aligned carbon nanotube compositefor supercapacitor application.Journal of Power Sources 2011,196(13), 5779-5783;(f)Sun,C.Y.;Zhu,Y.G.;Zhu,T.J.;Xie,J.;Cao,G.S.;Zhao,X.B., Co(OH)2/graphene sheet-on-sheet hybrid as high-performance electrochemicalpseudocapacitor electrodes.Journal of Solid State Electrochemistry 2013,17(4), 1159-1165;(g)Yan,Y.;Cheng,Q.;Zhu,Z.;Pavlinek,V.;Saha,P.;Li,C.,Controlledsynthesis of hierarchical polyaniline nanowires/ordered bimodal mesoporouscarbon nanocomposites with high surface area for supercapacitorelectrodes.Journal of Power Sources 2013,240(31),544-550.
[8]Huber,G.W.;Iborra,S.;Corma,A.,Synthesis of transportation fuelsfrom biomass:chemistry,catalysts,and engineering.Chemical Reviews 2006,106(9), 4044-4098.
[9](a)Mohan,D.;Pittman,C.U.;Steele,P.H.,Pyrolysis of Wood/Biomass forBio-Oil:A Critical Review.Energy&Fuels 2006,20(3),848--889;(b)Gong,Y.;Li, D.;Luo,C.;Fu,Q.;Pan,C.,Highly porous graphitic biomass carbon as advancedelectrode materials for supercapacitors.Green Chemistry 2017,19(17).
[10]Xu,B.;Sun,N.;Liu,H.,Facile synthesis of high performance hardcarbon anode materials for sodium ion batteries.Journal of MaterialsChemistry A 2015,3(41), 20560-20566.
[11](a)Jie,Z.;Li,B.;Wu,S.;Wei,Y.;Hui,W.,Chitin based heteroatom-dopedporous carbon as electrode materials for supercapacitors.CarbohydratePolymers 2017,173,321-329;(b)Rufford,T.E.;Hulicova-Jurcakova,D.;Zhu,Z.;Lu,G.Q., Nanoporous carbon electrode from waste coffee beans for highperformance supercapacitors.Electrochemistry Communications 2008,10(10),1594-1597;(c) Chen,Y.;Zhu,Y.;Wang,Z.;Li,Y.;Wang,L.;Ding,L.;Gao,X.;Ma,Y.;Guo,Y.,Application studies of activated carbon derived from rice husks produced bychemical-thermal process—A review.Advances in Colloid&Interface Science2011, 163(1),39-52.
[12]Xiao,K.;Ding,L.X.;Chen,H.;Wang,S.;Lu,X.;Wang,H.,Nitrogen-dopedporous carbon derived from residuary shaddock peel:a promising andsustainable anode for high energy density asymmetric supercapacitors.Journalof Materials Chemistry A 2015,4(2),372-378.
[13](a)Zhao,K.;Wei,J.;Luo,D.;Tang,Y.;Xu,L.,Fabrication ofhydroxyapatite porous scaffolds by freeze drying.Journal of the ChineseCeramic Society 2009,37 (3),432-435;(b)Han,D.;Mei,H.;Xiao,S.;Xia,J.;Gu,J.;Cheng,L.,Porous SiC nw/SiC ceramics with unidirectionally aligned channelsproduced by freeze-drying and chemical vapor infiltration.Journal of theEuropean Ceramic Society 2017,37 (3),915-921;(c)Wang,W.;Chen,M.;Chen,G.,Issues in Freeze Drying of Aqueous Solutions.中国化学工程学报(英文版)2012,20(3),551-559.
[14](a)Sun,H.;Xu,Z.;Gao,C.,Multifunctional,ultra-flyweight,synergistically assembled carbon aerogels.Advanced Materials 2013,25(18),2554-2560;(b)Yu,M.; Han,Y.;Li,J.;Wang,L.,CO2-activated porous carbon derivedfrom cattail biomass for removal of malachite green dye and application assupercapacitors.Chemical Engineering Journal 2017;(c)Mi,X.;Huang,G.;Xie,W.;Wang,W.;Liu,Y.;Gao,J., Preparation of graphene oxide aerogel and itsadsorption for Cu2+ions.Carbon 2012, 50(13),4856-4864.
[15](a)Xu,Z.;Zhang,Y.;Li,P.;Gao,C.,Strong,conductive,lightweight,neatgraphene aerogel fibers with aligned pores.ACS Nano 2012,6(8),7103-7113;(b)Wu, H.;Lu,L.;Zhang,Y.;Sun,Z.;Qian,L.,A facile method to prepare porousgraphene with tunable structure as electrode materials for immobilization ofglucose oxidase. Colloids&Surfaces A Physicochemical&Engineering Aspects2016,502,26-33;(c) Gong,H.P.;Hua,W.M.;Yue,Y.H.;Gao,Z.,Graphene oxide for acidcatalyzed-reactions:Effect of drying process.Appl.Surf.Sci.2017,397,44-48.
[16]Zhu,Y.;Murali,S.;Stoller,M.D.;Ganesh,K.J.;Cai,W.;Ferreira,P.J.;Pirkle, A.;Wallace,R.M.;Cychosz,K.A.;Thommes,M.,Carbon-based supercapacitorsproduced by activation of graphene.Science 2011,332(6037),1537.
[17]Jr,E.R.N.,Phenomenological Theory of Ion Solvation.EffectiveRadii of Hydrated Ions.Biochimica Et Biophysica Acta 1959,63(9),566-567.
[18](a)Ferrari,A.C.;Robertson,J.,Interpretation of Raman spectra ofdisordered and amorphous carbon.Physical Review B Condensed Matter 2000,61(20), 14095-14107;(b)Ferrari,A.C.;Meyer,J.C.;Scardaci,V.;Casiraghi,C.;Lazzeri,M.; Mauri,F.;Piscanec,S.;Jiang,D.;Novoselov,K.S.;Roth,S.,Ramanspectrum of graphene and graphene layers.Physical Review Letters 2006,97(18),187401.
[19]Yang,Z.;Yao,Z.;Li,G.;Fang,G.;Nie,H.;Liu,Z.;Zhou,X.;Chen,X.;Huang,S.,Sulfur-doped graphene as an efficient metal-free cathode catalyst foroxygen reduction.ACS Nano 2012,6(1),205-11.
Claims (6)
1.一种以芹菜为原料的超级电容器电极材料制备方法,其特征在于具体步骤如下:
(1)将芹菜用去离子水洗干净,切成小条;
(2)用液氮将小条状的芹菜快速冻结;
(3)将冻住的芹菜放在真空冷冻干燥机里,在冷阱温度为-40~-60℃,压强为1~10Pa的条件下冻干24~72h,室温前期为5~15℃,后期为25~30℃,最后4h用红外灯照射样品,使样品温度达到30~35℃,样品冻干后使干燥箱体内气压还原至大气压,取出样品;
(4)将冻干后的芹菜放在管式炉中,在Ar(20~1000sccm)的保护气氛中,炉子按2~15℃/min的升温速率加热至600~1000℃,恒温0.2~5h,待炉温冷却至室温后将样品取出,即得多级孔径分布的石墨化多孔碳材料;
(5)将所制备的多孔碳材料用玛瑙研钵研成粉末,然后按多孔碳:乙炔黑:聚四氟乙烯(PTFE)粘结剂=16:3:1的质量比将其在研钵中混合研磨均匀后,再均匀涂于不锈钢网集流体上,从而得到超级电容器电极;
(6)在1mol/L的H2SO4水溶液中,以所得石墨化多孔碳为工作电极、Ag/AgCl为参比电极、Pt丝为对电极构成三电极体系,对所得石墨化多孔碳材料进行电化学性能测试。
2.将权利要求1中步骤(1)-(5)所得石墨化多孔碳材料作为电极,在其内部填充聚乙烯醇/磷酸凝胶电解质,并在两个相同电极中间均匀涂布一层聚乙烯醇/磷酸凝胶状电解质,组装得到超级电容器。
3.根据权利要求1所述的电极,其特征在于原材料芹菜的纤维化程度比较高,且含有大量水分和养分输送通道,而且所含元素种类丰富。
4.根据权利要求1所述的电极材料,其特征在于比表面积达155~1700m2/g,孔径分布多级化,含有N,P,S等掺杂元素,以及一些含氧官能团。
5.根据权利要求2所述的一种以芹菜为原料的超级电容器,其特征在于组成电容器的电极在电流密度为1A/g时,比容量可达350F/g,在电流密度为10A/g下循环长达10万次后,比容量仍能保持在60%以上。
6.根据权利要求2所述的一种以芹菜为原料的超级电容器,其特征在于功率密度高达16.0kW/kg时,能量密度仍能达到16.3Wh/kg。
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Cited By (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN110124699A (zh) * | 2019-05-30 | 2019-08-16 | 河北科技大学 | 生物质碳管辅助MoS2析氢催化剂的制备方法及其应用 |
CN110931273A (zh) * | 2019-11-15 | 2020-03-27 | 北京纳米能源与系统研究所 | 凝胶电解质及其制备方法以及超级电容器及其应用 |
CN112289593A (zh) * | 2020-10-21 | 2021-01-29 | 西南大学 | 用于超级电容器的芹菜衍生活性碳材料及其制备方法和应用 |
CN115425229A (zh) * | 2022-11-04 | 2022-12-02 | 中科南京绿色制造产业创新研究院 | 一种正极添加剂及其制备方法和应用 |
Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN103943380A (zh) * | 2014-04-24 | 2014-07-23 | 陆艾珍 | 碳多孔电极的制备方法 |
CN104538202A (zh) * | 2014-12-31 | 2015-04-22 | 天津大学 | 一种双向可拉伸的超级电容器及其制备方法 |
CN106449135A (zh) * | 2016-07-11 | 2017-02-22 | 同济大学 | 一种基于有序碳纳米管复合膜的可拉伸电容器及其制备 |
CN107256805A (zh) * | 2017-06-01 | 2017-10-17 | 烟台大学 | 一种碳化的超级电容器电极材料及其制备方法和用途 |
CN107919233A (zh) * | 2017-10-16 | 2018-04-17 | 中国科学院电工研究所 | 一种高电压柔性固态超级电容器及其制备方法 |
-
2018
- 2018-12-04 CN CN201811473020.5A patent/CN109637843A/zh active Pending
Patent Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN103943380A (zh) * | 2014-04-24 | 2014-07-23 | 陆艾珍 | 碳多孔电极的制备方法 |
CN104538202A (zh) * | 2014-12-31 | 2015-04-22 | 天津大学 | 一种双向可拉伸的超级电容器及其制备方法 |
CN106449135A (zh) * | 2016-07-11 | 2017-02-22 | 同济大学 | 一种基于有序碳纳米管复合膜的可拉伸电容器及其制备 |
CN107256805A (zh) * | 2017-06-01 | 2017-10-17 | 烟台大学 | 一种碳化的超级电容器电极材料及其制备方法和用途 |
CN107919233A (zh) * | 2017-10-16 | 2018-04-17 | 中国科学院电工研究所 | 一种高电压柔性固态超级电容器及其制备方法 |
Non-Patent Citations (1)
Title |
---|
YOUNING GONG 等: ""Highly porous graphitic biomass carbon as advanced electrode materials for supercapacitors"", 《GREEN CHEMISTRY》 * |
Cited By (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN110124699A (zh) * | 2019-05-30 | 2019-08-16 | 河北科技大学 | 生物质碳管辅助MoS2析氢催化剂的制备方法及其应用 |
CN110931273A (zh) * | 2019-11-15 | 2020-03-27 | 北京纳米能源与系统研究所 | 凝胶电解质及其制备方法以及超级电容器及其应用 |
CN112289593A (zh) * | 2020-10-21 | 2021-01-29 | 西南大学 | 用于超级电容器的芹菜衍生活性碳材料及其制备方法和应用 |
CN115425229A (zh) * | 2022-11-04 | 2022-12-02 | 中科南京绿色制造产业创新研究院 | 一种正极添加剂及其制备方法和应用 |
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