聚酰亚胺基高比表面活性炭及其电化学性能研究

doi:10.15541/jim20170049

摘要/Abstract

摘要：

以聚酰亚胺(PI)薄膜边角料为前驱体, 采用CO₂物理活化法制备高比表面活性炭。研究了活化工艺对PI活性炭孔结构性能的影响及其活化机理, 探讨了活性炭孔结构对其电化学性能的影响。结果表明, PI薄膜可以在相对较低的温度下经CO₂活化制备出具有无定型微晶质炭结构、孔隙结构发达的活性炭, 比表面积最高可达2809 m²/g, 总孔容积达1.423 cm³/g; 通过控制CO₂活化工艺, 可实现对PI活性炭的孔道尺度与分布的调控。作为超级电容器电极材料, PI活性炭在100 mA/g条件下, 比电容高达237 F/g, 电容保持率为86%。孔径集中于0.7~2 nm, 并存在适量介孔的活性炭具有极佳的电化学性能。

关键词: 聚酰亚胺薄膜, 活性炭, CO₂活化, 高比表面积, 电化学性能

Abstract:

Polyimide-based activated carbon (PIAC) was prepared by CO₂ activation using polyimide (PI) film offcut as precursor. The influences of activation conditions on the pore structure of PI-based activated carbons and the activation mechanism were investigated. Effects of pore structure on electrochemical properties of PIAC were also investigated. Results show that the PI film offcuts can be used to prepare the PI-based activated carbon with high surface area, abundant porosity and amorphous carbon structure at relatively low temperature via CO₂ activation, in which the highest specific surface area was 2809 m²/g with pore volume of 1.423 cm³/g. Pore size and distribution of activated carbon can effectively be concentrated at 0.7-2 nm with proper mesopores by controlling CO₂ activation time. As an electrode material, PIAC shows an excellent electrochemical performance with specific capacitance of up to 237 F/g at current density of 100 mA/g and capacitance retention of 86%.

Key words: polyimide film, activated carbon, CO₂ activation, high specific surface, electrochemical performance

中图分类号:

TQ127

王浩, 李琳, 王春雷, 王倩, 梁长海, 王同华. 聚酰亚胺基高比表面活性炭及其电化学性能研究[J]. 无机材料学报, 2017, 32(11): 1181-1187.

WANG Hao, LI Lin, WANG Chun-Lei, WANG Qian, LIANG Chang-Hai, WANG Tong-Hua. Preparation and Electrochemical Performance of Polyimide-based Activated Carbons with High Surface Area[J]. Journal of Inorganic Materials, 2017, 32(11): 1181-1187.

图/表 10

图1 活化时间对PIAC吸附性能和产率的影响

Fig. 1 Effect of activation time on the adsorption properties and yield of PIAC

表1 PIAC的孔结构参数

Table 1 Porous textural parameters deduced from N2 adsorption for PIAC

Sample	S_BET/(m²·g^-1)	V_tot/(cm³·g^-1)	V_mic/(cm³·g^-1)	V_meso/(cm³·g^-1)	(V_meso/V_tot)/%	C_g/(F·g^-1)
PIAC-2	1229	0.510	0.484	0.026	5	182
PIAC-4	1811	0.792	0.737	0.055	7	212
PIAC-6	2120	1.043	0.854	0.189	18	237
PIAC-8	2809	1.423	1.067	0.356	25	233

图2 PIAC的(a) 吸脱附等温线和(b) DFT孔径分布曲线 Fig. 2 N2 adsorption / desorption isotherms (a) and pore size distributions (b) of DFT Inset is the micropore distributions by HK equation for PIAC

图3 PIAC的孔径分布柱状图

Fig. 3 Histogram of pore size distributions for PIAC

表2 采用不同前驱体的活性炭性能比较

Table 2 Comparison of performance of AC prepared from different precursors

Precursor	T /℃	Time/h	S_BET/(m²•g^-1)	V_tot/(cm³•g^-1)
Coconut shells^[12]	900	5.0	1653.0	1.045
Anthracite^[13]	920	3.0	1071.0	0.45
Depleted fullerene soot^[14]	900	2.0	938.0	0.56
PFA^[15]	900	5.0	1150.0	0.45
Corn stalk acid hydrolysis residue^[16]	1000	3.5	845.4	-
Coffee endocarp^[17]	900	3.0	1038.0	0.460
PI film in this work	880	2.0	1229.0	0.510
PI film in this work	880	4.0	1811.0	0.792

图4 PIAC的XRD图谱

Fig. 4 XRD patterns of PIAC

图5 PIAC-t的(a) N1s谱图和(b) O1s图谱

Fig. 5 N1s spectra (a) and O1s spectra (b) of PIAC-t

图6 (a) PIAC-t 在2 mV/s下的循环伏安曲线和(b)PIAC-6在不同扫速下的循环伏安曲线

Fig. 6 CV curves of PIAC-t at scan rate of 2 mV/s (a) and PIAC-6 at different scanning rates (b)

图7 PIAC在(a)100 mA/g电流密度下的恒流充放电和(b)不同电流密度下的质量比电容

Fig. 7 GCD of PIAC at current density of 100 mA/g (a) and specific capacitance of PIAC at different current densities (b)

图8 PIAC的交流阻抗谱图

Fig. 8 AC impedance spectra of PIAC (a) Nyquist plot with the inset showing the expanded high-frequency region; (b) Bode plot

参考文献 26

[1]	MA C, SHI J L, LI Y J,et al. Preparation of nitrogen-enriched porous carbon nanofibers and their electrochemical performance as electrode materials of supercapacitors. New Carbon Materials, 2015, 30(4): 295-301.
[2]	QIN Z X.The introduction of polyimide.Information Recording Materials, 2010, 11(5): 63-64.
[3]	WU G G.The manufacture and application of polyimide and film.Information Recording Materials, 2010, 11(5): 47-53.
[4]	LI B, DAI F, XIAO Q,et al. Nitrogen-doped activated carbon for a high energy hybrid supercapacitor. Energy & Environmental Science, 2016, 9(1): 102-106.
[5]	TAER E, DERAMAN M, TALIB I A,et al. Physical, electrochemical and supercapacitive properties of activated carbon pellets from pre-carbonized rubber wood sawdust by CO2 activation. Current Applied Physics, 2010, 10(4): 1071-1075.
[6]	FARMA R, DERAMAN M, AWITDRUS A,et al. Preparation of highly porous binderless activated carbon electrodes from fibres of oil palm empty fruit bunches for application in supercapacitors. Bioresource Technology, 2013, 132(3): 254-261.
[7]	WANG T H, JIAO T T, CHAI C L.A study of recovering gasoline vapor on activated carbon.Petroleum Processing and Petrochemicals, 2009, 40(9): 60-65.
[8]	SIRCAR S, GOLDEN T C, RAO M.B. Activated carbon for gas separation and storage.Carbon, 1996, 34(1): 1-12.
[9]	YUE Z R, JIANG W, WANG L,et al. Surface characterization of electrochemically oxidized carbon fibers. Carbon, 1999, 37(11): 1785-1796.
[10]	SI W J, WU X Z, XING W,et al. Bagasse-based nanoporous carbon for supercapacitor application. Journal of Inorganic Materials, 2011, 26(1): 107-112.
[11]	HU C, SEDGHI S, MADANI S H,et al. Control of the pore size distribution and its spatial homogeneity in particulate activated carbon. Carbon, 2014, 78(18): 113-120.
[12]	YANG K B, PENG J H, XIA H Y,et al. Preparation of coconut shells-based activated carbons with CO2 activation. Carbon Techniques, 2010, 29(1): 20-23.
[13]	袁翠翠. CO2活化制备煤基微孔活性炭的研究. 徐州: 中国矿业大学硕士学位论文, 2016.
[14]	SUN L, WANG C L, ZHOU Y,et al. Activated carbons produced form depleted fullerene soot by carbon dioxide activation and their electrochemical properties. New Carbon Materials, 2014, 29(2): 55-60.
[15]	QAJAR A, MARYAM P, RAJAGOPALAN R,et al. Surface compression of light adsorbates inside microporous PFA- derived carbons. Carbon, 2013, 60(12): 538-561.
[16]	SI H Y, SUN K, CHEN L,et al. Orthogonal experimental study on activated carbon from biomass hydrolysis residues activated by carbon dioxide. Chemical Industry and Engineering Progress, 2014, 33(s1): 141-144.
[17]	NABAIS J M V, TEIXEIRA J G, ALMEIDA I. Development of easy made low cost bindless monolithic electrodes from biomass with controlled properties to be used as electrochemical capacitors.Bioresource Technology, 2011, 102(3): 2781-2787.
[18]	YANG H, GONG M C, CHEN Y Q.Effect of size distribution on adsorption capacities of activated carbons for CH4 and CO2.Chinese Journal of inorganic Chemistry, 2011, 27(6): 1053-1058.
[19]	DENG M G, WANG R Q, FENG Y H.Effect of petroleum coke expanding by HNO3 on the performance of supercapacitor based on the activated carbon.Journal of Inorganic Materials, 2014, 29(3): 245-249.
[20]	FENG Y Q, TANG F L, LANG J W,et al. Facile approach to preparation of nitrogen-doped graphene and its supercapacitive performance. Journal of Inorganic Materials, 2013, 28(6): 677-682.
[21]	DENISA H J, MYKOLA S, GAO Q L,et al. Combined effect of nitrogen- and oxygen-containing functional group of microporous activated carbon on its electrochemical performance in supercapacitors. Advanced Functional Materials, 2009, 19(3): 438-447.
[22]	MONTES-MORÁN M A, SUÁREZ D, MENÉNDEZ J A,et al. On the nature of basic sites on carbon surfaces: an overview. Carbon, 2004, 42(7): 1219-1225.
[23]	HUANG W, ZHANG Y, BAO S,et al. Desalination by capacitive deionization process using nitric acid-modified activated carbon as the electrodes. Desalination, 2014, 340(1): 67-72.
[24]	VIX-GUTERL C, FRACKOWIAK E, JUREWICZ K,et al. Electrochemical energy storage in ordered porous carbon materials. Carbon, 2005, 43(6): 1293-1302.
[25]	GRYGLEWICZ G, MACHNIKOWSKI J, LORENC G E,et al. Effect of pore size distribution of coal-based activated carbons on double layer capacitance. Electrochimica Acta, 2005, 50(5): 1197-1206.
[26]	LAUŠEVIĆ Z, APEL P Y, KRSTIĆ J B,et al. Porous carbon thin films for electrochemical capacitors. Carbon, 2013, 64: 456-463.