1. Organic solvent boosts charge storage and charging dynamics of conductive MOF supercapacitors
- Author
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Chen, Ming, Wu, Taizheng, Niu, Liang, Ye, Ting, Dai, Wenlei, Zeng, Liang, Kornyshev, Alexei A., Wang, Zhenxiang, Liu, Zhou, and Feng, Guang
- Subjects
Physics - Applied Physics ,Condensed Matter - Materials Science - Abstract
Conductive metal-organic frameworks (c-MOFs) and ionic liquids (ILs) have emerged as auspicious combinations for high-performance supercapacitors. However, the nanoconfinement from c-MOFs and high viscosity of ILs slow down the charging process. This hindrance can, however, be resolved by adding solvent. Here, we performed constant-potential molecular simulations to scrutinize the solvent impact on charge storage and charging dynamics of MOF-IL-based supercapacitors. We find conditions for >100% enhancement in capacity and ~6 times increase in charging speed. These improvements were confirmed by synthesizing near-ideal c-MOFs and developing multiscale models linking molecular simulations to electrochemical measurements. Fundamentally, our findings elucidate that the solvent acts as an ionophobic agent to induce a substantial enhancement in charge storage, and as an ion traffic police to eliminate convoluted counterion and co-ion motion paths and create two distinct ion transport highways to accelerate charging dynamics. This work paves the way for the optimal design of MOF supercapacitors.
- Published
- 2024