A high-strength, environmentally stable, and recyclable starch/PVA organohydrogel electrolyte for flexible all-solid-state supercapacitor

Advance Technologies in Biodegradable Flexible Solid‐State Supercapacitors: A Mini Review on Clean and Sustainable Energy

“…In another recent study, authors utilized the freezing-thawing technique and utilized PVA, starch, dimethyl sulfoxide, and calcium chloride to prepare green hydrogel electrolyte with having broad working temperature range (À 20 °C to 80 °C), flexibility, good mechanical properties, and recyclability. [69] Due to the involvement of starch-like natural polymers, it potentially promises biodegradability. Not only biodegradability cellulose-based electrolytes have also shown self-healing capability (~94 % healing efficiency).…”

“…This ionic liquid‐activated PE has exhibited λ of 1.9 mS cm −1 . In another recent study, authors utilized the freezing‐thawing technique and utilized PVA, starch, dimethyl sulfoxide, and calcium chloride to prepare green hydrogel electrolyte with having broad working temperature range (−20 °C to 80 °C), flexibility, good mechanical properties, and recyclability [69] . Due to the involvement of starch‐like natural polymers, it potentially promises biodegradability.…”

Engineering chitosan into a recyclable and flame-resistant gel electrolyte via a dual cross-linking strategy for flexible supercapacitors

“…25,26 Given that the possible severe damage of GPEs will lead to their significant degradation or total disappearance of their favourable properties, recyclable hydrogel electrolytes can repair the damage by reprocessing into gels again for the next application without generating waste, demonstrating a significant feature from a sustainable point of view. For example, based on the reversible dynamic physical interaction between starch and PVA segments, He et al prepared a recyclable organohydrogel electrolyte via a thermoplastic process, which could be melted by heating to 90 °C for 30 min, and then recycled into a new gel by freezing at −20 °C for 3 h. 27 Huang et al prepared a novel hydrogel electrolyte based on dynamic and reversible interactions of hydrogen bonds and ion complexes. When completely dried and ground into powder, the hydrogel could be reshaped by adding a few drops of water.…”

Wide-Temperature-Range Flexible Supercapacitors Using a Multipurpose Organogel Electrolyte

“…First of all, traditional hydrogel electrolytes contain a large amount of solvent water, which will inevitably freeze at subzero temperatures, significantly weakening the ionic conductivity or even losing. Second, at high temperature or room temperature, the internal water molecules cannot exist stably and are volatile, resulting in a loss of performance. − Finally, the operating voltage of hydrogel electrolytes is generally just within a relatively small potential window (0.8–1.0 V), which is because when the voltage reaches 1.23 V, the water will split, limiting its energy density. , At present, the study of wide-temperature-resistant hydrogel electrolytes has made a breakthrough, but there are still some places that can be improved in this field. − The most common strategy is to introduce organic solvent (glycerin, dimethyl sulfoxide, and ethylene glycol) into hydrogels, , but the introduction of organogels using novel antifreeze is rarely reported. , At the same time, the introduction of organic solvents usually weakens the mechanical properties and ionic conductivity of the hydrogel electrolytes . So, designing a new gel electrolyte with a wide temperature range, excellent mechanical properties, and capacitive properties is a great challenge.…”