Regenerated hydrogel electrolyte towards an all-gel supercapacitor

Abstract

Electrolyte regeneration is an important goal for environmental protection and sustainable development efforts. Herein, we report a facile strategy inspired by the transformation of edible dough from flour to regenerate hydrogel electrolytes from their dehydrated copolymer granules (CGs) via direct addition of water or salt solution. With the aid of heating, this procedure is efficient, relatively quick, and easily implemented. The dehydrated CGs are lightweight, reusable and stable under long-term storage. Even after 5 cycles of dehydration and regeneration, the regeneration efficiency of the hydrogel electrolytes, as evaluated based on retention of mechanical strength, is over 60%. The regenerated electrolytes possess considerable ionic conductivity, reprocessability, and 3D-printability. Furthermore, an all-gel supercapacitor assembled from the regenerated hydrogel electrolyte and activated carbon electrode with CGs as binder demonstrates excellent interfacial compatibility. The assembled all-gel supercapacitor can maintain 98.7% of its original specific capacitance after 100 bending tests, and can operate in a wide temperature range spanning from −15 to 60°C. This work may provide a new access to the development of renewable materials for various applications in the fields of intelligent devices, wearable electronics and soft robotics.

Flexible electrochemical energy storage devices and related applications: recent progress and challenges

“…Hydrogel electrolytes, due to their excellent mechanical strength, reproducibility, and plasticity, can serve as a suitable substrate for 3D printing. For instance, Wang et al 84 developed a robust hydrogel by random copolymerization of 3-(methacryloylamino)-propyl trimethylammonium chloride and methacrylic acid, utilizing various interactions such as hydrophilic hydrogen bonding and polyanionic interactions along with entanglement of hydrophobic polymer chains ( Fig. 7g ).…”

Insight of super-capacitive properties of flexible gel polymer electrolyte containing butyl imidazole ionic liquids with different anions based on PVDF-HFP

“…However, the utilization of ionic liquid gel polymer electrolytes is currently limited due to its status as a nascent eld, which necessitates further investigation of various issues, and there is still considerable room for improvement in some of its properties [22][23]. There are many types of imidazolium ionic liquids, and different structures have a large impact on the gel polymers formed by imidazolium ionic liquids, which can effectively enhance the speci c capacitance and energy of the supercapacitors [24][25]. However, there have been very few reports of supercapacitors assembled from ionic liquids with different anions, which introduces many uncertainties to the application of ionic liquids in supercapacitors.…”

Multifunctional Antifreezing Organogel Polyelectrolyte for a Flexible Supercapacitor

“…With the continuous progress and development of wearable electronic technology, flexible electronic products with the characteristics of portability, wearability, collapsibility, miniature, and lightweight have been paid more and more attention. − As we know, in lots of energy storing devices, flexible solid-state supercapacitors have become one of the most hopeful flexible energy storage devices due to their large specific capacitance, rapid charging and discharging properties, wonderful stability, and excellent mechanical properties. − The rational design of electrode or electrolyte materials − and the optimization of device configuration have become the direction of development to build high-performance flexible supercapacitors (FSCs). Conductive gels with intrinsic flexibility, significant mechanical recycling, and remarkable ionic conductivity can not only be used as ideal materials for FSC electrolytes − but also have considerable applications in tissue engineering, drug delivery, water treatment, bioengineering, and many other fields.…”