-
超级电容器作为当今新型电能储存器件,其性能介于电池与静电电容器之间,具有循环寿命长、充放电速度快、高能量密度、经济环保等优点,应用于大功率电动汽车及航天航空领域中[1-2]。超级电容器按储能方式可分为两种,由电极材料与电解液形成的界面双电层进行储能的称为双电层电容器(EDLC);通过电极材料表面发生氧化还原反应来实现能量的存储与转化的称为赝电容器(pseudocapacitors)[3-4]。由能量密度公式E=1/2 C×V2(式中E、C、V分别表示能量密度、比电容和测试电压)可知[5],通过优化电解质与电极材料能够提升能量密度,相比于改善电解质,开发具有特定官能团结构、比表面积大、孔道结构与电解质适配的新型电极材料处于超级电容器研究的前沿[6-8]。
碳电极材料以其来源丰富、使用寿命长、比电容量高、安全环保等优点,成为超级电容器应用最广的电极材料,占据了当前市场的80%[2,9-11]。然而,高质量的碳材料合成工艺往往比较复杂,生产成本昂贵。因此,开发经济、环保、高性能的碳电极材料至关重要[12]。生物质原料具有循环再生、绿色经济和规模化生产等优热势,已成为超电容器电极材料研究新热点[13]。碳材料电极的电容性能主要取决于碳材料碳、氮、氧等化学结构和含量以及碳材料微介孔分布,而这些物化结构与碳材料制备原料密切相关[13-17]。天津科技大学Wei等[14]研究表明,以玉米穗、玉米叶、小麦秆为原料制备的碳材料电容性能不同,这主要是由于制备的生物质材料木质素、纤维素以及微量元素等不同引起的。而且,研究还表明,经N、P等杂原子掺入能够明显改善碳材料的表面性能,产生额外的赝电容,提高电极材料的比电容量。如Sevilla等[15]通过水热法制得氮掺杂多孔碳材料,测得比电容为50—60 F·g−1,高于纯相碳纳米管的20 F·g−1;王会杰等[16]以乙二胺为氮源,制备出高比表面积氮掺杂活性炭,测得比电容高达370 F·g−1,高于无氮掺杂组份的337 F·g−1。
本文用棉秆(CS)和棉秆纤维(CSF)为碳源,以三聚氰胺为氮掺杂剂,制备氮掺杂棉秆碳材料(NCSC)和氮掺杂棉秆纤维碳材料(NCSFC),通过对两者孔结构、表面化学以及电容性能进行对比,研究NCSC与NCSFC碳电极材料的电容性能差异及原因。
棉秆与棉秆纤维基纳米碳材料的结构及电容性能对比分析
Comparative analysis of structure and capacitance properties of cotton stalk fiber-based and cotton stalk fiber-based of nano-carbon materials
-
摘要: 以棉秆和棉秆纤维作为碳源,三聚氰胺为氮源,在800 ℃氮气气流下制备出氮掺杂棉秆碳(NCSC)和氮掺杂棉秆纤维碳(NCSFC)。采用傅立叶变换红外光谱(FT-IR)、X射线光电子能谱(XPS)、N2吸/脱附和恒流充放电法表征了2种碳材料的组成、结构、表面性质和比电容,对比分析了2种碳材料的碳-氧-氮元素含量、官能团结构和电容性能。结果表明,除碳元素含量外,氮掺杂棉秆纤维碳NCSFC表面N/O化学官能团、比表面积(1155 m2·g−1)和介孔孔容(2.485 cm3·g−1),均明显高于氮掺杂棉秆碳NCSC。但后者NCSC的比电容高达 195 F·g−1,远高于NCSFC(90 F·g−1),这主要归因于制备NCSC碳的原材料为棉秆,棉秆中富含木质素,制备的NCSC中碳元素含量显著高于棉秆纤维碳NCSFC,形成的芳环碳结构提升了碳材料电极电子储存性能。Abstract: Cotton stalk and cotton stalk fiber as carbon source, melamine as nitrogen sources, nitrogen doped cotton stalk carbon (NCSC) and nitrogen doped cotton stalk fiber carbon (NCSFC) were prepared under a nitrogen gas flow at 800 ℃. Fourier transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS), N2 absorption/desorption and constant current charge-discharge methods were used to characterize the composition, structure, surface properties and specific capacitance of the two carbon materials. The carbon - oxygen - nitrogen content、composition、structure、surface properties and specific capacitance of the two carbon materials were compared and analyzed. The results show that in addition to the carbon content, the surface of NCSFC has N/O chemical functional groups、specific surface area (1155 m2· g−1) and mesopore volume (2.485 cm3 · g−1), are significantly higher than NCSC. However, the specific capacitance of NCSC is as high as 195 F·g−1, which is much higher than NCSFC (90 F·g−1). This is mainly due to the fact that the carbon source for the preparation of NCSC comes from cotton stalks, which are rich in lignin, making the carbon content of NCSC is significantly higher than NCSFC and the formed aromatic carbon structure improves the electron storage performance of carbon material electrodes.
-
Key words:
- cotton stalk /
- cotton stalk fiber /
- biochar /
- structure /
- capacitance performance
-
图 4 (a)不同扫描速率下NCSC的CV曲线;(b)不同扫描速率下NCSFC的CV曲线;(c)NCSC、NCSFC在0.5 A·g−1电流密度下的GCD曲线;(d)NCSC、NCSFC在10 A·g−1电流密度下的GCD曲线
Figure 4. (a)CV curves of NCSC at different scan rates;(b)CV curves of NCSFC at different scan rates;(c)GCD curve of NCSC and NCSFC at a current density of 0.5 A·g−1;(d)GCD curves of NCSC and NCSFC at a current density of 10 A·g−1
-
[1] 郭坤琨, 陈鹏, 李柱. 氮掺杂多孔碳的制备及其电化学性能研究 [J]. 湖南大学学报(自然科学版), 2018, 45(6): 78-84. GUO K K, CHEN P, LI Z. Preparation of nitrogen-doped porous carbon and its electrochemical properties [J]. Journal of Hunan University (Natural Science), 2018, 45(6): 78-84(in Chinese).
[2] 李忠裕, 李云同, 吴雯倩, 等. 磷掺杂中空碳球的制备及其电容性能研究 [J]. 材料工程, 2020, 48(3): 105-111. doi: 10.11868/j.issn.1001-4381.2018.000747 LI Z Y, LI Y T, WU W Q, et al. Preparation of phosphorus-doped hollow carbon balls and their capacitive properties [J]. Materials Engineering, 2020, 48(3): 105-111(in Chinese). doi: 10.11868/j.issn.1001-4381.2018.000747
[3] 辛冉冉, 胡庚申, 姜伟, 等. 氮掺杂高比表面多孔碳的一步化学活化法制备及其超电容性能 [J]. 无机化学学报, 2019, 35(10): 1781-1790. doi: 10.11862/CJIC.2019.222 XIN R R, HU G S, JIANG W, et al. Preparation of nitrogen-doped porous carbon with high specific surface by one-step chemical activation method and its supercapacitance performance [J]. Chinese Journal of Inorganic Chemistry, 2019, 35(10): 1781-1790(in Chinese). doi: 10.11862/CJIC.2019.222
[4] KIM N D, KIM W, JI B J, et al. Electrochemical capacitor performance of N-doped mesoporous carbons prepared by ammoxidation [J]. Journal of Power Sources, 2008, 180(1): 671-675. doi: 10.1016/j.jpowsour.2008.01.055 [5] 魏颖, 陶明松, 朱耀锋, 等. GNs/[Bmim][BF4]复合材料的制备及其超电容性能 [J]. 化工学报, 2020, 71(1): 417-425. WEI Y, TAO M S, ZHU Y F, et al. Preparation of GNs/[Bmim] [BF4] composite material and its supercapacitor performance [J]. Journal of Chemical Industry and Engineering, 2020, 71(1): 417-425(in Chinese).
[6] 张来苹, 张明亮, 张文帅, 等. ∝-Ni(OH)2 /石墨烯纳米复合材料的制备及其电容性能研究 [J]. 电子元件与材料, 2019, 38(12): 28-33. ZHANG L P, ZHANG M L, ZHANG W S, et al. Preparation of ∝-Ni(OH)2 / graphene nanocomposite and its capacitive properties [J]. Electronic Components and Materials, 2019, 38(12): 28-33(in Chinese).
[7] 王永芳, 左宋林. 含磷活性炭作为双电层电容器电极材料的电化学性能 [J]. 物理化学学报, 2016, 32(2): 481-492. doi: 10.3866/PKU.WHXB201511041 WANG Y F, ZUO S L. Electrochemical performance of phosphorus-containing activated carbon as electrode material for electric double layer capacitors [J]. Chinese Journal of Physical Chemistry, 2016, 32(2): 481-492(in Chinese). doi: 10.3866/PKU.WHXB201511041
[8] 王 昀, 贲腾. 海藻基含杂原子碳材料的制备及电化学性质 [J]. 高等学校化学学报, 2018, 39(12): 2627-2636. doi: 10.7503/cjcu20180297 WANG Y, BEN T. Preparation and electrochemical properties of algae-based heteroatom-containing carbon materials [J]. Chemical Journal of Chinese Universities, 2018, 39(12): 2627-2636(in Chinese). doi: 10.7503/cjcu20180297
[9] 李诗杰, 韩奎华. 活性炭孔结构及电化学性能协同优化 [J]. 化工进展, 2020, 39(1): 287-293. LI S J, HAN K H. Collaborative optimization of activated carbon pore structure and electrochemical performance [J]. Progress in Chemical Industry, 2020, 39(1): 287-293(in Chinese).
[10] 李金宏, 周岐雄, 米红宇, 等. 基于煤萃取物的类石墨状多孔炭的制备及其电容性能研究 [J]. 无机材料学报, 2016, 31(1): 39-46. doi: 10.15541/jim20150329 LI J H, ZHOU Q X, MI H Y, et al. Preparation of graphite-like porous carbon based on coal extraction and its capacitive properties [J]. Journal of Inorganic Materials, 2016, 31(1): 39-46(in Chinese). doi: 10.15541/jim20150329
[11] 于晶, 高利珍, 李雪莲, 等. 葱叶一步法裂解制备多孔炭及其电容性能研究 [J]. 新型炭材料, 2016, 31(5): 475-484. doi: 10.1016/S1872-5805(16)60026-4 YU J, GAO L Z, LI X L, et al. Porous carbon prepared by onion leaf cracking and its capacitance properties [J]. New Carbon Materials, 2016, 31(5): 475-484(in Chinese). doi: 10.1016/S1872-5805(16)60026-4
[12] 杨康, 帅骁睿, 杨化超, 等. 基于室温离子液体的活化石墨烯粉末超级电容储能性能 [J]. 物理化学学报, 2019, 35(7): 755-765. doi: 10.3866/PKU.WHXB201810009 YANG K, SHUAI X R, YANG H C, et al. Energy storage performance of activated graphene powder supercapacitors based on room temperature ionic liquids [J]. Chinese Journal of Physical Chemistry, 2019, 35(7): 755-765(in Chinese). doi: 10.3866/PKU.WHXB201810009
[13] 李丹青, 张霞, 许元栋. 生物炭的制备及其在超级电容器中的应用研究进展 [J]. 工程管理与技术, 2018, 39(23): 196-198. LI D Q, ZHANG X, XU Y D. Research progress of biochar preparation and its application in supercapacitors [J]. Engineering Management and Technology, 2018, 39(23): 196-198(in Chinese).
[14] WEI H G, WANG H, LI A, et al. Advanced porous hierarchical activated carbon derived from agricultural wastes toward high performance supercapacitors [J]. Journal of Alloys and Compounds, 2020: 820. [15] SEVILLA M, YU L H, ZHAO L, et al. Surface modification of CNTs with N-Doped carbon: an effective way of enhancing their performance in Supercapacitors [J]. Acs sustainable Chemistry & Engineering, 2014, 2(4): 1049-1055. [16] 王会杰, 王月娟, 胡庚申. 氮掺杂微孔活性炭制备及其超级电容性能 [J]. 工业催化, 2018, 26(6): 39-44. doi: 10.3969/j.issn.1008-1143.2018.06.008 WANG H J, WANG Y J, HU G S. Preparation of nitrogen-doped microporous activated carbon and its supercapacitor performance [J]. Industrial Catalysis, 2018, 26(6): 39-44(in Chinese). doi: 10.3969/j.issn.1008-1143.2018.06.008
[17] LI K Q, LIU J M, LI B J, et al. Effects of N mono- and N/P dual-doping on H2O2, ·OH generation, and MB electrochemical degradation efficiency of activated carbon fiber electrodes [J]. Chemosphere, 2018, 193: 800-810. doi: 10.1016/j.chemosphere.2017.11.111 [18] 李坤权, 李博宇. 介孔蔗渣碳的氮官能化改性及其对Hg2+ 吸附的影响 [J]. 材料研究学报, 2018, 32(12): 929-935. doi: 10.11901/1005.3093.2018.190 LI K Q, LI B Y. Nitrogen functional modification of mesoporous bagasse carbon and its effect on Hg2+ adsorption [J]. Journal of Materials Research, 2018, 32(12): 929-935(in Chinese). doi: 10.11901/1005.3093.2018.190
[19] LI K Q, JIANG Y, WANG X H, et al. Effect of nitric acid modification on the lead(II) adsorption of mesoporous biochars with different mesopore size distributions [J]. Clean Technol. Environ. Policy, 2016, 18: 797-805. doi: 10.1007/s10098-015-1056-0 [20] 禹兴海, 罗齐良, 潘剑, 等. 一种生物炭基柔性固态超级电容器的制备及性能研究 [J]. 化工学报, 2019, 70(9): 3590-3600. YU X H, LUO Q L, PAN J, et al. Preparation and performance study of a biochar-based flexible solid supercapacitor [J]. Chemical Journal of China, 2019, 70(9): 3590-3600(in Chinese).
[21] 高秀丽, 王丹丹, 李 硕, 等. 介孔碳微球的氢醌改性及电容性能研究 [J]. 无机材料学报, 2018, 33(1): 48-52. doi: 10.15541/jim20170134 GAO X L, WANG D D, LI S, et al. Hydroquinone modification and capacitance performance of mesoporous carbon microspheres [J]. Journal of Inorganic Materials, 2018, 33(1): 48-52(in Chinese). doi: 10.15541/jim20170134
[22] 王晓亮, 闫慧妍, 张佳齐, 等. Mn掺杂和还原氧化石墨烯复合对NiAl-LDHs超级电容性能的影响 [J]. 有色金属工程, 2019, 9(10): 13-20. doi: 10.3969/j.issn.2095-1744.2019.10.003 WANG X L, YAN H Y, ZHANG J Q, et al. Effect of Mn-doped and reduced graphene oxide composite on the performance of NiAl-LDHs supercapacitors [J]. Nonferrous Metals Engineering, 2019, 9(10): 13-20(in Chinese). doi: 10.3969/j.issn.2095-1744.2019.10.003
[23] 吴青松, 杨海平, 陈应泉, 等. 亚铁盐对生物质碳结构及电容特性的影响 [J]. 太阳能学报, 2017, 38(8): 2055-2061. WU Q S, YANG H P, CHEN Y Q, et al. Effect of ferrous salt on biomass carbon structure and capacitance characteristics [J]. Journal of Solar Energy, 2017, 38(8): 2055-2061(in Chinese).
[24] 张 玲, 董 伟, 李文翠. 间苯二酚-明胶-甲醛共聚体系制备三维网状含氮多孔炭及其电容性能 [J]. 新型炭材料, 2016, 31(4): 386-392. ZHANG L, DONG W, LI W C. Preparation of three-dimensional network nitrogen-containing porous carbon with resorcinol-gelatin-formaldehyde copolymerization system and its capacitive properties [J]. New Carbon Materials, 2016, 31(4): 386-392(in Chinese).
[25] 屈笑笑, 邢宝林, 康伟伟, 等. 玉米芯电容炭的制备及其电化学性能 [J]. 化工进展, 2018, 37(6): 2340-2346. QU X X, XING B L, KANG W W, et al. Preparation and electrochemical performance of corncob capacitor carbon [J]. Chemical Industry and Engineering Progree, 2018, 37(6): 2340-2346(in Chinese).
[26] 史长亮, 邢宝林, 曾会会, 等. 梯级孔生物质活性炭的制备及其电容特性研究 [J]. 材料导报(A), 2018, 32(10): 3318-3324. SHI C L, XING B L, ZENG H H, et al. Preparation of cascade pore biomass activated carbon and its capacitance characteristics [J]. Materials Review (A), 2018, 32(10): 3318-3324(in Chinese).
[27] HULICOVA-JURCAKOVA D, SEREDYCH M, LU G Q, et al. Combined effect of nitrogen- and oxygen-containing functional groups of microporous activated carbon on its electrochemical performance in supercapacitors [J]. Advanced Functional Materials, 2009, 19(3): 438-447. doi: 10.1002/adfm.200801236 [28] 高丽丽. 超级电容器用聚丙烯腈基活性碳纤维的直接活化制备及性能研究[D]. 长春: 吉林大学, 2014. GAO L L. Direct activation preparation and properties of polyacrylonitrile-based activated carbon fibers for supercapacitors[D]. Changchun: Jilin University, 2014 (in Chinese).