多孔碳在不同电解液中的电容性能研究  

Study on Capacitive Performance of Porous Carbonsin Different Electrolytes

作　　者：熊枫 杨梦召 刘庆雷[1] XIONG Feng;YANG Mengzhao;LIU Qinglei(The State Key Laboratory of Metal Matrix Composites,Shanghai Jiao Tong University,Shanghai 200240,China)

机构地区：[1]上海交通大学金属基复合材料国家重点实验室,上海200240

出　　处：《中国材料进展》2023年第9期732-739,共8页Materials China

基　　金：国家自然科学基金项目(51772187,52072241);上海市科委基础研究项目(18JC1410500)。

摘　　要：多孔碳材料凭借其低成本和高循环稳定性的优势成为目前商业双电层超级电容器(electrical double-layer supercapacitor, EDLC)的主要活性材料,其孔结构对容量和倍率性能有着决定性影响。在保持测试条件一致的前提下,系统地比较了5种不同孔径分布的多孔碳在水系电解液(1 mol·L~(-1) H_2SO_4)、有机电解液(ACN/EMIMBF_4)和离子液体电解液(EMIMBF_4)中的性能差异。研究结果表明,微孔和介孔分别在提高比容量和倍率性能上具有各自的优势。此外,研究还发现向纯离子液体中添加乙腈(ACN)溶剂不仅可以整体提高5种多孔碳的倍率性能,同时还能在一定程度上缩小微孔碳材料与介孔碳材料在容量保持率上的差距,弥补微孔材料倍率性能上的不足。当混合电解液中ACN的比例增加时,多孔碳材料的倍率性能逐渐提升,并在ACN和EMIMBF_4的体积比为3∶1时达到稳定值;而容量则是先增大后减小,在ACN和EMIMBF_4体积比为1∶3时达到最大值。本研究为目前以微孔活性炭为主的超级电容器的性能提升提供了借鉴。Due the their advantages of low cost and high cycle stability,porous carbons have dominated the active material market of commercial electrical double-layer supercapacitor(EDLC).Their pore structures definitely have a critical impact on the capacitance and rate performance.Based on the same test conditions,here we systematically tested the capacitive performance of five kinds of porous carbons with different pore size distribution in aqueous electrolyte(1 mol·L-1 H 2 SO 4),organic electrolyte(ACN/EMIMBF 4)and ionic liquid electrolyte(EMIMBF 4).The results show that micropores and mesopores have their own advantages in improving specific capacitance and rate performance,respectively.Additionally,we found that adding ACN solvent to pure ionic liquid can not only improve the rate performance of five kinds of porous carbons,but also narrow the gap in capacitance retention between microporous carbons and mesoporous carbons.When the volume ratio of ACN in mixed electroplyte increases,the rate performance gradually improves and reaches a stable value when the volume ratio of ACN and EMIMBF 4 is 3∶1;the capacitance increases at first and then decreases,the maximum value corresponds to the volume ratio of ACN and EMIMBF 4 reaching 1∶3.This study provides a reference for the works mainly based on microporous activated carbon to improve the performance of supercapacitors.

关 键 词：双电层超级电容器 多孔碳 孔结构 离子液体 有机溶剂 

分 类 号：TB332[一般工业技术—材料科学与工程] TM912[电气工程—电力电子与电力传动]