Author:
Wang Hongrui,Zhao Qingyuan,Lai Kang,Bao Nanyun,Zhou Weibin,Deng Qi,Fu Zhiqiang,Dai Jiayu,Wu Xiongwei,Zeng Xianxiang
Abstract
AbstractLithium-selenium (Li-Se) batteries possess high volumetric capacity and have attracted considerable attention as a high energy storage system. However, the shuttling of polyselenides seriously worsens the electrochemical performance and retards their application advancement. Herein, we engineered a bifunctional membrane consisted of polyethylenimine derived carbon quantum dots (Cdots) to efficiently restrict the shuttling of polyselenides under a high Se loading (Se≈70 wt%) and promote Li-Se conversion kinetics, which can be accounted by the greatly accelerated transportation of charge carriers and dipole–dipole interactions between polar moieties and long-chain polyselenides (Li2Se4 and Li2Se6) as corroborated by theoretical calculations. Thus, the bifunctional membrane endows Li-Se batteries with a specific capacity of 658.60 mAh g−1 at 0.1 C and coulombic efficiency of 97.8% in average, and demonstrates the effectiveness of defect-rich Cdots on suppressing polyselenides shuttling and reinforcing Li-Se conversion kinetics in augmenting the battery’s durability and efficiency.
Graphical Abstract
Funder
National Natural Science Foundation of China
Key Technologies Research and Development Program
the Natural Science Foundation of Hunan province
Natural Science Foundation of Hunan province
the foundation from Education Department of Hunan Province
Publisher
Springer Science and Business Media LLC