Supramolecular Gel Electrolyte-Based Supercapacitors with a Comparable Dependence of Electrochemical Performances on Electrode Thickness to Those Based on Bulk Electrolyte Solutions

Gel polymer electrolyte (GPE)-based quasi-solid-state supercapacitors (QSSCs) have attracted great interest in the last 10 years due to the increasing demand of wearable electronics. However, the strong dependence of electrochemical performances on the electrode thickness of the GPE-based QSSCs severely limits their applications. Herein, a low-molecular-weight supramolecular gel electrolyte (SGE) has been successfully developed to render the SGE-based QSSCs a comparable dependence of electrochemical performances on electrode thickness to those based on bulk electrolyte solutions. Two main reasons are responsible for such an observation. First, the as-prepared SGE has an ionic conductivity as high as ∼421 mS cm–1. Second, the combined advantages of small molecular size, low solution viscosity, and good wettability endow the SGE with a capability to effectively infill the thick porous activated carbon electrodes through a sol–gel transition method. Moreover, it has also been demonstrated that the SGE developed here is applicable to a wide range of QSSCs.