冷冻干燥辅助一步碳化-活化壳聚糖基多孔碳的制备及电化学性能  

Preparation and Electrochemical Properties of Freeze-Drying-Assisted One-step Carbonization-Activated Chitosan-based Porous Carbon

作　　者：周亚丽 雷西萍[1,2] 樊凯 于婷 关晓琳 ZHOU Yali;LEI Xiping;FAN Kai;YU Ting;GUAN Xiaolin(School of Materials Science and Engineering,Xi’an University of Architecture and Technology,Xi’an 710055,China;Key Laboratory of Nanomaterials and Technology,Shaanxi Province,Xi’an 710055,China;School of Chemistry and Chemical Engineering,Northwest Normal University,Lanzhou 730070,China)

机构地区：[1]西安建筑科技大学材料科学与工程学院,西安710055 [2]陕西省纳米材料与技术重点实验室,西安710055 [3]西北师范大学化学化工学院,兰州730070

出　　处：《材料导报》2023年第5期209-216,共8页Materials Reports

基　　金：“超级电容器电极材料设计与应用”团队建设资金;生态环境相关高分子材料教育部重点实验室开放基金(KF-18-01)。

摘　　要：本工作采用冷冻干燥辅助一步碳化-活化法制备了壳聚糖基多孔碳(CSPC),利用扫描电子显微镜(SEM)、X射线衍射仪(XRD)、拉曼光谱分析仪(Raman)、X射线光电子能谱仪(XPS)和氮气吸脱附实验(BET)对不同活化剂比例下材料的结构形貌及化学组成进行表征,探究了其电化学性能。结果表明:CSPC表面粗糙,比表面积高达2 178.9 m^(2)·g^(-1),具有显著的分级多孔结构和较高的中孔率,并含氮、氧等杂原子,赋予电极材料较好的导电性、良好的润湿性和高离子扩散率,使其表现出优异的电容特性。当活化剂与壳聚糖质量比为1∶1时,多孔碳(CSPC-1.0)在0.5 A·g^(-1)的电流密度下,比容量高达386.0 F·g^(-1),当电流密度为20 A·g^(-1)时,其比电容仍然高达319.6 F·g^(-1),表现出优异的倍率性能;同时,在5 A·g^(-1)的电流密度下,电极经过10 000次充放电循环后容量保持率为94.4%,表现出优异的循环稳定性。以CSPC-1.0为电极活性物质组装成对称超级电容器,在功率密度300 W·kg^(-1)时,其能量密度可达15.5 Wh·kg^(-1)。本工作制备的具有分级结构的壳聚糖基多孔碳作为储能材料具有广阔的应用前景。Chitosan-based porous carbon materials(CSPC) were prepared by a one-step carbonization-activation supplemented with a freeze-drying method. The structural morphology and chemical composition of the materials prepared at different activator ratios were characterized by scanning electron microscopy(SEM), X-ray diffraction(XRD), Raman spectroscopy(Raman), X-ray photoelectron spectroscopy(XPS) and nitrogen adsorption and desorption test(BET), and their electrochemical properties were investigated. The test results show that CSPC had a rough surface with a high specific surface area of 2 178.9 m^(2)·g^(-1), a hierarchical porous structure and a high mesoporosity, and was rich in heteroatoms such as nitrogen and oxygen, which endows the electrode material with good electrical conductivity, good wettability and fast ion diffusion performance, enabling it to exhibit excellent capacitive properties. When the mass ratio of activator to chitosan was 1∶1, the specific capacity of porous carbon(CSPC-1.0) was as high as 386.0 F·g^(-1) at a current density of 0.5 A·g^(-1), and when the current density was 20 A·g^(-1), its specific capacitance was still as high as 319.6 F·g^(-1), showing excellent rate performance;meanwhile, at a current density of 5 A·g^(-1), the electrode had 94.4% specific capacity retention after 10 000 charge/discharge cycles, showing excellent cycling stability. A symmetrical supercapacitor assembled with CSPC-1.0 as the electrode active substance could achieve an energy density of 15.5 Wh·kg^(-1) at a power density of 300 W·kg^(-1). The chitosan-based porous carbon with a hierarchical structure prepared in this work has a promising application as an energy storage material.

关 键 词：壳聚糖 多孔碳 冷冻干燥 电化学性能 超级电容器 

分 类 号：TB332[一般工业技术—材料科学与工程]