Reviewed by Lexie CornerApr 25 2024
A recent study published in the journal npj Flexible Electronics by researchers from the Pohang University of Science and Technology and Korea Institute of Industrial Technology revealed the creation of a small-scale energy storage device that can bend, twist, fold, and wrinkle.
Professor Jin Kon Kim and Dr. Keon-Woo Kim. Image Credit: Pohang University of Science and Technology
The efforts were made by Professor Jin Kon Kim, Dr. Keon-Woo Kim, and Researcher Seong Ju Park from the Korea Institute of Industrial Technology (KITECH), as well as Dr. Chanwoo Yang from Pohang University of Science and Technology (POSTECH).
Energy storage technologies that can match the suppleness and stretchability of soft electronic devices are desperately required in light of the emergence of wearable technology. Micro supercapacitors (MSCs) have gained traction as a viable option for deformable energy storage because of their extended cycle life, high power density, and quick charging.
However, because brittle materials like gold (Au) have been frequently used as electrodes, the fabrication of interdigitated electrode patterns capable of maintaining the energy storage performance under repeated stretching and twisting has remained a great challenge. Despite the high conductivity and deformability of eutectic gallium-indium liquid metal (EGaIn), the material’s extremely high surface tension makes fine patterning of EGaIn very challenging.
The research team successfully created fine patterning on a stretchable polystyrene-block-poly (ethylene-co-butylene)-block-polystyrene copolymer (SEBS) substrate by using a laser to create both EGaIn and graphene (acting as an active material) layers. The stretchable SEBS substrate beneath the EGaIn and graphene layers was not harmed during laser ablation, preserving the MSC device’s flexibility.
After stretching for up to 1,000 cycles, the resulting MSC's areal capacitance does not change from its initial value. The manufactured MSCs function steadily even when subjected to various mechanical deformations, such as folding, twisting, wrinkling, and stretching.
The use of laser-patterned liquid metal electrodes represents a significant step forward in the development of truly deformable energy storage solutions. As wearable technologies continue to advance, innovations like these will play a vital role in ensuring that our devices can adapt to the demands of our dynamic lifestyles.
Jin Kon Kim, Professor, Pohang University of Science and Technology
The Korea Institute of Industrial Technology's industry-leading Core Production Technology Development Project and the Ministry of Economy and Finance of the Republic of Korea provided financial resources for this research through the National Creative Research Initiative Program.
Journal Reference:
Kim, K., et al. (2024) Deformable micro-super capacitor fabricated via laser ablation patterning of Graphene/liquid metal. npj Flexible Electronics. doi.org/10.1038/s41528-024-00306-2