Optimal Design of a Small-Molecule Crowding Electrolyte and Molecular Dynamics Simulation of an Electrode-Electrolyte Interface for Aqueous Supercapacitors with a Wide Operating Temperature Range

作者：Wu, Di; Feng, Hua Jie^*; Xu, Li Hua; Zhang, Wen Yu; Zhang, Zhong Jie; Chen, Xiang Ying^*; Cui, Peng^*

来源：ACS Applied Energy Materials, 2022, 5(1): 355-366.

DOI：10.1021/acsaem.1c02889

• wide temperature range
• small-molecule crowding electrolytes
• hydrogen bond interaction
• molecular dynamics simulations
• high-voltage aqueous supercapacitors

Designing a high-voltage aqueous electrolyte with a wide temperature range is essential to realize low-cost and high-safety supercapacitors (SCs). However, the theoretical decomposition voltage of water seriously limits the energy density and practical application. Herein, we propose a simple strategy to form small-molecule crowding electrolytes (SMCEs) by modulating the hydrogen bond network of water and ion interaction via ethylene glycol (EG). Therefore, the working voltage and specific capacitance of activated carbon-based SCs using SMCEs increase to 1.8 V and 165 F g(-1), respectively. Significantly, molecular dynamics simulations reveal that the highly crowded environment induced by EG makes most of the water molecules be squeezed out of the electrode-electrolyte interfacial region, thereby inhibiting the H2O electrolysis on the surface of the charged electrode. This work provides an innovative strategy for the application of high-voltage aqueous SCs.

• 单位
  海南师范大学