Led by Sungjune Park, PhD, a professor and soft electronics expert, the team used liquid metal particles to create a new hydrogel electrolyte.
According to the researchers, it could reportedly help power wearable electronics and flexible energy storage devices in harsh climates.
A new flexible hydrogel The growth of wearable and bio-integrated electronics has increased the need for flexible energy storage systems that can withstand bending, stretching, and harsh environmental conditions without losing performance.
The researchers used liquid metal particles (LMPs) as initiators for polymerization, the chemical process used to form the hydrogel network.
Moreover, energy storage devices built using the materials retained 98 percent of their performance after 45,000 charge-discharge cycles.
Scientists in South Korea have unveiled an ultra-stretchable hydrogen electrolyte that can expand up to 900 percent of its original size while staying fully functional at subzero temperatures. The study came from Sungkyunkwan University’s (SKKU) Department of Chemical Engineering. Led by Sungjune Park, PhD, a professor and soft electronics expert, the team used liquid metal particles to create a new hydrogel electrolyte.
The new material can stretch up to nine times its original length without losing its electrochemical performance. It also remains functional at temperatures as low as -4 degrees Fahrenheit (-20 degrees Celsius). According to the researchers, it could reportedly help power wearable electronics and flexible energy storage devices in harsh climates. “For practical applications, it is essential to ensure long-term stability and reproducibility in large-area manufacturing processes,” the research group pointed out. A new flexible hydrogel The growth of wearable and bio-integrated electronics has increased the need for flexible energy storage systems that can withstand bending, stretching, and harsh environmental conditions without losing performance. Meanwhile, even though conventional hydrogel electrolytes are flexible and boast high ionic conductivity, they often lack mechanical strength. In addition, they also freeze at low temperatures, which limits their practical use.
Тo address the challenge, the SKKU team decided to build a hydrogel electrolyte. The researchers used liquid metal particles (LMPs) as initiators for polymerization, the chemical process used to form the hydrogel network. Schematic illustration of the fabrication process and device structure of the liquid metal-based hydrogel electrolyte.
Credit: Zhang, Q., Bhuyan, P., Nguyen, Q.T. et al. The particles combine liquid-like adaptability and metallic properties. This makes them highly versatile for applications like flexible electronics, drug delivery, and soft robotics. The team then used ultrasonication, a technique that uses high-frequency sound waves to agitate and process materials, and broke the bulk liquid metal into fine particles. These, in turn, initiated the polymerization of acrylamide and acrylic acid to form the hydrogel. The method works without heat, UV light, or other external stimuli, which makes manufacturing easier. Liquid metal solution At the same time, the researchers also incorporated stearyl methacrylate (SMA), a hydrophobic material that forms physical crosslinks between polymer chains. These reversible connections can break under stress to absorb energy and then reform once the stress is removed.
This gave the hydrogel exceptional durability and stretchability. Tests revealed it could stretch up to nine times its original length before breaking. It corresponded to an elongation at break of approximately 900 percent. The researchers then soaked the hydrogel in a lithium chloride solution. This step suppressed hydrogen bonding between water molecules, prevented freezing, and preserved its flexibility. Consequently, the electrolyte maintained both ionic conductivity and mechanical performance at temperatures of -4 degrees Fahrenheit, unlike traditional hydrogel systems. Moreover, energy storage devices built using the materials retained 98 percent of their performance after 45,000 charge-discharge cycles. Park highlighted the innovation’s significance. “This work introduces a new design strategy for hydrogel electrolytes based on liquid metal and provides a viable platform for next-generation wearable electronics and flexible energy storage systems operating under extreme conditions,” he concluded in a press release.
The study has been published in the journal Nano-Micro Letters.
