Hierarchically porous carbon foams for electric double layer capacitors

作     者：Feng Zhan Tianyu Liu Guihua Hou Tianyi Kou Lu Yue Rongfeng Guan Yat Li 

作者机构：Key Laboratory for Advanced Technology in Environmental Protection of Jiangsu Province Yancheng Institute of Technology Yancheng 224051 China Department of Chemistry and Biochemistry University of California Santa Cruz 1156 High Street Santa Cruz CA 95064 USA 

出 版 物：《Nano Research》 (纳米研究（英文版）)

年 卷 期：2016年第9卷第10期

页      面：2875-2888页

核心收录：

学科分类：080801[工学-电机与电器] 0808[工学-电气工程] 080901[工学-物理电子学] 0809[工学-电子科学与技术（可授工学、理学学位）] 08[工学] 0805[工学-材料科学与工程（可授工学、理学学位）] 0702[理学-物理学] 

基　　金：This work was supported by Jiangsu Government Scholarship for overseas studies  National Nature Science Foundation of China (Nos. 11204266 and 21276220)  and Nature Science Foundation of Jiangsu Province (Nos. BK20141262 and BK20140463). The authors thank Dr. Tom Yuzvinsky from University of California  Santa Cruz for SEM images acquisition and acknowledge the W. M. Keck Center for Nanoscale Opto-fluidics for use of the FEI Quanta 3D Dual-beam scanning electron microscope. The authors also acknowledge Prof. Zhonghua Zhang from Shandong University for his help with BET characterization  Prof. Jin Z. Zhang from University of California  Santa Cruz  for offering the access to Reinshaw Raman spectrometer  Mr. Fuxin Wang from Sun Yat-sen University for TEM characterization  Prof. Xiaoxia Liu and Mr. Yu Song from Northeastern University for their generous help with AFM characterization 

主　　题：hierarchically porouss tructure glutaraldehyde-crosslinked chitosan light weight carbon foam electrical double layer capacitors 

摘      要：The growing demand for portable electronic devices means that lightweight power sources are increasingly sought after. Electric double layer capacitors （EDLCs） are promising candidates for use in lightweight power sources due to their high power densities and outstanding charge/discharge cycling stabilities. Three-dimensional （3D） self-supporting carbon-based materials have been extensively studied for use in lightweight EDLCs. Yet, a major challenge for 3D carbon electrodes is the limited ion diffusion rate in their internal spaces. To address this limitation, hierarchically porous 3D structures that provide additional channels for internal ion diffusion have been proposed. Herein, we report a new chemical method for the synthesis of an ultralight （9.92 mg/cm3） 3D porous carbon foam （PCF） involving carbonization of a glutaraldehyde- cross-linked chitosan aerogel in the presence of potassium carbonate. Electron microscopy images reveal that the carbon foam is an interconnected network of carbon sheets containing uniformly dispersed macropores. In addition, Brunauer-Emmett-Teller measurements confirm the hierarchically porous structure. Electrochemical data show that the PCF electrode can achieve an outstanding gravimetric capacitance of 246.5 F/g at a current density of 0.5 A/g, and a remarkable capacity retention of 67.5% was observed when the current density was increased from 0.5 to 100A/g. A quasi-solid-state symmetric supercapacitor was fabricated via assembly of two pieces of the new PCF and was found to deliver an ultra-high power density of 25 kW/kg at an energy density of 2.8 Wh/kg. This study demonstrates the synthesis of an ultralight and hierarchically porous carbon foam with high capacitive performance.