Flexible Supercapacitor Technologies and Hydrogel Electrolytes

Flexible supercapacitors represent a rapidly advancing class of energy storage devices that combine high power density with mechanical compliance, making them well suited to wearable electronics, soft robotics and flexible sensors. Central to their performance is the integration of stretchable electrodes and gel or quasi‐solid‐state electrolytes, often based on hydrogels, which provide both ionic conductivity and mechanical resilience. Hydrogel electrolytes, composed of crosslinked polymer networks swollen by aqueous or ionic liquids, offer tunable properties such as high ionic mobility, self-healing capacity, stretchability and environmental adaptability, including low-temperature tolerance. By selecting natural or synthetic polymers, introducing supramolecular interactions or incorporating nanofillers, researchers have tailored the electrolyte structure to balance conductivity, robustness and multifunctionality. Advances in device architectures—from countertop two-dimensional films to all‐in‐one fibre or textile formats—have further enhanced energy and power outputs while preserving flexibility. Together, these developments underpin a global effort to create safer, greener and more versatile energy storage solutions for next-generation portable and wearable technologies.

Research from Nature Portfolio

Building on foundational work, one study introduced a double cross-linked hydrogel electrolyte combining clay nanosheets and graphene oxide, achieving extraordinary mechanical stretchability exceeding 1000% strain alongside high ionic conductivity. Devices fabricated with wrinkled-structure electrodes maintained performance after repeated healing by infrared irradiation or heating. Another contribution demonstrated a multi-responsive healable supercapacitor, where magnetic and photothermal triggers enable rapid self-repair of a magneto-activated polyacrylamide hydrogel. By embedding electroactive nanoparticles into the healing matrix, the assembled device delivered record areal capacitance and restored nearly original capacity over multiple healing cycles. Earlier research showcased a polyampholyte hydrogel electrolyte paired with biochar‐reduced-graphene-oxide electrodes, resulting in flexible, self-healing devices operable down to −30 °C with high energy density and stable cycling retention, highlighting the promise for low-temperature applications.

Flexible Supercapacitor Technologies and Hydrogel Electrolytes publication trend

The graph below shows the total number of articles in flexible supercapacitor technologies and hydrogel electrolytes across all publications each year (not limited to Nature Index journals).

Technical terms

Hydrogel electrolyte: A network of hydrophilic polymers swollen with water or ionic solution that conducts ions while providing mechanical flexibility.

Quasi-solid-state: A gel-like medium that combines the safety and stability of a solid with the high ionic mobility of a liquid electrolyte.

Self-healing: The ability of a material to autonomously repair mechanical damage through reversible chemical or physical interactions.

Specific capacitance: A measure of charge stored per unit mass or area of electrode material, expressed in farads per gram or farads per square centimetre.

Supramolecular interaction: Non-covalent bonds (e.g. hydrogen bonding, host–guest inclusion) used to impart dynamic behaviour such as healing or reversible crosslinking.

References

1. Ultrastretchable and superior healable supercapacitors based on a double cross-linked hydrogel electrolyte. Nature Communications (2019).
2. A multi-responsive healable supercapacitor. Nature Communications (2021).
3. Flexible and Self-Healing Aqueous Supercapacitors for Low Temperature Applications: Polyampholyte Gel Electrolytes with Biochar Electrodes. Scientific Reports (2017).
4. Recent Advances in Biopolymer-Based Hydrogel Electrolytes for Flexible Supercapacitors. ACS Energy Letters (2024).
5. High‐Strength Self‐Healable Supercapacitor Based on Supramolecular Polymer Hydrogel with Upper Critical Solubility Temperature. Advanced Functional Materials (2024).
6. Self‐Healing and Shape‐Editable Wearable Supercapacitors Based on Highly Stretchable Hydrogel Electrolytes. Advanced Science (2022).