Compatibility electrode-electrolyte interface through supramolecular gel polymer electrolyte for flexible energy storage

Hydrogel electrolytes have attracted extensive attention in the field of flexible energy storage due to their excellent flexibility and high safety. However, the insufficient mechanical properties and low ion conductivity severely limit the development of high-performance flexible energy storage devices. In response to this challenge, this study constructed a three-dimensional supramolecular ion gel electrolyte (SPAA-Zn), which effectively locks anions and active water molecules through the rich hydrogen bond and coordination bond interactions between sodium alginate, metal ions and anions. This supramolecular network synergistically enhances the mechanical properties of the electrolyte and ionic conductivity (12.75 mS cm -1 ), significantly improving ion transport efficiency and promoting electrode electrolyte interface stability. The symmetrical flexible ionic gel supercapacitor (AC//SPAA- Zn//AC) based on SPAA-Zn assembly still maintains 84% capacity retention and 97% coulomb efficiency after 1000 cycles. This device exhibits good flexibility, deformability, and compressive performance simultaneously. This study provides a valuable idea for the design of high-performance hydrogel electrolytes for flexible supercapacitors. • A supramolecular dual-network gel electrolyte is constructed via synergistic ionic/hydrogen bonds, achieving high ionic conductivity (12.75 mS cm -1 ) and enhanced mechanical strength. • The supramolecular structure locks anions and water molecules, suppressing water splitting and extending the voltage window of flexible supercapacitors to 1.4 V. • The assembled flexible supercapacitor exhibits outstanding cycling stability (84% after 1000 cycles) and mechanical flexibility (86% retention at 180 o bending).