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 ele...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.展开更多
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)+4 种基金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 Teamsthe 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
文摘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.
