Mitigating self-discharge of activated carbon-based supercapacitors with hybrid liquid crystal as an electrolyte additive

摘要

The application of supercapacitors has been restricted partially due to the high self-discharge rate and large leakage current. In this paper, a nematic hybrid liquid crystal, E7, is adopted as an additive to the electrolyte, and the self-discharge of activated carbon-based supercapacitors is evaluated by tuning various parameters such as initial voltage, current density, temperature and thickness of electrodes. Our results show that the super capacitors exhibit an obviously lower self-discharge rate due to the contribution of E7, evidenced by the 24 h open circuit potential (OCP) drop from 3 V to 1.4 V with E7, compared to the 24 h OCP drop to 1.1 V in the situation without E7. The leakage current is also reduced from 10 to 2.2 mu A with the existence of E7.