在600℃～1100℃对聚偏二氯乙烯(PVDC)树脂仅进行炭化处理,制备了一系列PVDC基活性炭.由TG、XRD和N_2吸附等温线(77 K)分别测定了PVDC基炭经历的热解过程与其晶型、比表面积和孔结构;采用循环伏安、交流阻抗和恒电流充放电考察了它们在质量分数30%的 KOH水溶液中的电容特性.结果表明:PVDC基炭属于无定形碳,其大的比表面积(874.5m~2/g～969.2m~2/g)和丰富的微孔在固相炭化过程中形成;PVDC基炭具有适于双电层形成的优异孔径分布、高的质量比电容和面积比电容;900℃炭化的PVDC基炭具有最高的比电容值和良好的功率特性,50mA/g电流密度时的放电比电容达256.9F/g,5000mA/g电流密度时的放电比电容保持率达76.5%;提高炭化温度可提高PVDC基炭的电导率,降低电解质离子在孔内的扩散阻抗,改善双电层电容器的功率性能.
A series of poly vinylidene chloride (PVDC) based activated carbons was prepared by carbonization at 600-1 100 ℃. Their formation, crystallinity, surface area and pore structure were characterized by thermogravimetry, X-ray diffraction and nitrogen adsorption. The electrochemical performance was investigated by cycle voltammetry, AC impedance and galvanostatic charge/discharge in a 30 % (mass fraction) KOH electrolyte. Results showed that the structure of PVDC-based carbons was amorphous and their high surface area (874-969 m~2/g) and abundant micropores were formed during the solid phase carbonization. PVDC-based carbon had a high gravimetric capacitance and specific capacitance per surface area, owing to its optimum pore size distribution suitable for the formation of electric double layers. The PVDC-based carbon heat-treated at 900 ℃ had a maximum capacitance and an excellent power performance. The specific capacitance can reach as high as 256.9 F/g at low discharge current density (50 mA/g) and the capacitance retention ratio is 76.5% at high current density (5 000 mA/g). The electrical conductivity of PVDC-based carbon increased and the diffusion resistance of electrolyte ions in pores decreased with increasing carbonization temperature, and the rate performance of the electric double layer capacitor is improved as a result.
参考文献
| [1] | R. Kotz;M. Carlen .Principles and applications of electrochemical capacitors[J].Electrochimica Acta,2000(15/16):2483-2498. |
| [2] | Qu D Y;Shi H .Studies of activated carbons used in double-layer capacitors[J].Journal of Power Sources,1998,74(01):99-107. |
| [3] | D. Lozano-Castello;D. Cazorla-Amoros;A. Linares-Solano .Influence of pore structure and surface chemistry on electric double layer capacitance in non-aqueous electrolyte[J].Carbon: An International Journal Sponsored by the American Carbon Society,2003(9):1765-1775. |
| [4] | 刘希邈,詹亮,滕娜,杨登莲,曾小春,张睿,凌立成.超级电容器用沥青焦基活性炭的制备及其电化学性能[J].新型炭材料,2006(01):48-53. |
| [5] | 李强,李开喜,王芙蓉,孙国华.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[J].新型炭材料,2005(04):335-342. |
| [6] | S.-I. Lee;S. Mitani;S.-H. Yoon .Preparation of spherical activated carbon with high electric double-layer capacitance[J].Carbon: An International Journal Sponsored by the American Carbon Society,2004(11):2332-2334. |
| [7] | 刘辰光,刘敏,王茂章,成会明.电化学电容器中炭电极的研究及开发Ⅱ.炭电极[J].新型炭材料,2002(02):64-72. |
| [8] | 森本 剛 .電気二重層キャパシタの開発と工業化の現状[J].炭素,2004(214):202-209. |
| [9] | Yagi S;Kawaguchi M;Yamanaka T.The effect of electrolyte on electric double layer capacitance of nitrogen-rich C/N material[A].Gyeongju:02-03. |
| [10] | Lee S I;Mitani S;Park C W et al.Electric double-layer capacitance of microporous carbon nano spheres prepared through precipitation of aromatic resin pitch[J].Journal of Power Sources,2005,139(1-2):379-383. |
| [11] | 安部郁夫;長谷川貴洋 .ナノ細孔炭素の製造法と孔径制御技術[J].炭素,2005(218):197-201. |
| [12] | 竹田敏和;遠藤守信.硫酸水溶液電気二重層キャパシタの開発と応用[J].炭素,1999(189):179-187. |
| [13] | M. Endo;Y.J. Kim;T. Takeda .Poly(vinylidene chloride)-Based Carbon as an Electrode Material for High Power Capacitors with an Aqueous Electrolyte[J].Journal of the Electrochemical Society,2001(10):A1135-A1140. |
| [14] | Koresh J;Soffer A .Stereoselectivity in ion electroadsorption and in double-layer charging of molecular sieve carbon electrodes[J].Journal of Electroanalytical Chemistry,1983,147:223-234. |
| [15] | Shi H .Activated carbon and double layer capacitance[J].Electrochimica Acta,1996,41(10):1633-1639. |
| [16] | Soshi Shiraishi;Hideyuki Kurihara;Lan Shi .Electric Double-Layer Capacitance of Meso/Macroporous Activated Carbon Fibers Prepared by the Blending Method[J].Journal of the Electrochemical Society,2002(7):A855-A861. |
| [17] | 侯朝辉 .高比表面积中孔炭材料的制备及其双电层电容性能研究[D].中南大学,2004. |
| [18] | Kinoshita K.Carbon:Electrochemical and Physicochemical Properties[M].New York:Kodansa Press,1988 |
| [19] | Gyoung-Ja Lee;Su-Il Pyun .Effect of microcrystallite structures on electrochemical characteristics of mesoporous carbon electrodes for electric double-layer capacitors[J].Electrochimica Acta,2006(15):3029-3038. |
- 下载量()
- 访问量()
- 您的评分：
-
10%
-
20%
-
30%
-
40%
-
50%