Mitigating self-discharge of carbon-based electrochemical capacitors by modifying their electric-double layer to maximize energy efficiency  

作　　者：Yu-Zuo Wang Xu-Yi Shan Da-Wei Wang Hui-Ming Cheng Feng Li 

机构地区：[1]Key Laboratory for Anisotropy and Texture of Materials,Northeastern University,Shenyang 110819,Liaoning,China [2]Shenyang National Laboratory for Materials Science,Institute of Metal Research,Chinese Academy of Sciences,Shenyang 110016,Liaoning,China [3]China Aviation Lithium Battery Technology Co.Ltd,Luoyang 471000,Henan,China [4]School of Chemical Engineering,The University of New South Wales,Sydney NSW 2052,Australia [5]Shenzhen Geim Graphene Center,Tsinghua-Berkeley Shenzhen Institute,Tsinghua University,Shenzhen 518055,Guangdong,China [6]School of Materials Science and Engineering,University of Science and Technology of China,Shenyang 110016,Liaoning,China

出　　处：《Journal of Energy Chemistry》2019年第11期214-218,共5页能源化学（英文版）

基　　金：supported by the National Natural Science Foun-dation of China (Nos. 51525206 , 51521091 and 51172239);the Ministry of Science and Technology of China(2016YFA0200100 ,2016YFB0100100);the Strategic Priority Research Program of Chinese Academy of Science (XDA22010602);the Key Research Program of Chinese Academy of Sciences (Grant No. KGZD-EWT06);the Program for Guangdong Introducing Innovative and Enterpreneurial Teams;the Strategic Priority Research Program of Chinese Academy of Science (No. XDA22010602);the Development and Reform Commission of Shenzhen Municipality for the development of the “Low-Dimensional Materials and Devices” discipline

摘　　要：Self-discharge is a significant issue in electric double layer energy storage, which leads to a rapid voltage drop and low energy efficiency. Here, we attempt to solve this problem by changing the structure of the electric double layer into a de-solvated state, by constructing a nano-scale and ion-conductive solid electrolyte layer on the surface of a carbon electrode. The ion concentration gradient and potential field that drive the self-discharge are greatly restricted inside this electric double layer. Based on this understanding, a high-efficiency graphene-based lithium ion capacitor was built up, in which the self-discharge rate is reduced by 50% and the energy efficiency is doubled. The capacitor also has a high energy density, high power output and long life, and shows promise for practical applications.Self-discharge is a significant issue in electric double layer energy storage, which leads to a rapid voltage drop and low energy efficiency. Here, we attempt to solve this problem by changing the structure of the electric double layer into a de-solvated state, by constructing a nano-scale and ion-conductive solid electrolyte layer on the surface of a carbon electrode. The ion concentration gradient and potential field that drive the self-discharge are greatly restricted inside this electric double layer. Based on this understanding, a high-efficiency graphene-based lithium ion capacitor was built up, in which the self-discharge rate is reduced by 50% and the energy efficiency is doubled. The capacitor also has a high energy density, high power output and long life, and shows promise for practical applications.

关 键 词：ELECTRIC double layer SELF-DISCHARGE GRAPHENE LITHIUM ion CAPACITOR 

分 类 号：F42[经济管理—产业经济]