New fiber material boosts energy storage for wearable devices

Carbon nanotube fibers fabricated into fiber-like supercapacitors (FSSCs) demonstrate their energy storage capabilities and wearable properties in a commercially available digital watch. Credit: Korea Institute of Science and Technology.

Researchers in South Korea have developed a groundbreaking fiber material that significantly enhances the energy storage capacity of wearable devices, making them more efficient and durable.

This new development could revolutionize wearable technology, such as health-monitoring rings and virtual reality headsets, by overcoming existing limitations in battery size and life.

The research, conducted by Dr. Hyeonsu Jeong, Namdong Kim from the Center for Functional Composite Materials, Jeonbuk Branch, and Dr. Seungmin Kim from the Center for Carbon Fusion Materials, was published in the journal Advanced Energy Materials.

Their work introduces a new type of electrode material, shaped like a fiber, which is both strong and highly flexible.

Traditionally, wearable devices have struggled with limited battery life due to their small size. To address this, the team focused on carbon nanotube fibers, known for their lightweight and excellent electrical properties.

However, these fibers typically require additional materials to function as effective energy storage, making them costly and less durable over time.

The breakthrough came when the researchers developed a way to enhance the carbon nanotubes themselves, increasing their surface area and electrochemical activity through acid treatment and a process called spinning.

This modification allows the fibers to store much more energy—33 times more than traditional carbon nanotube fibers. They also offer greater mechanical strength and electrical conductivity.

What makes this development especially promising is the durability of the new fibers.

In tests, fiber-shaped supercapacitors made from the new material maintained nearly perfect performance even when knotted or bent 5,000 times.

They also held up well when woven into the wrist straps of digital watches, surviving bending, folding, and washing without loss of function.

This innovation not only extends the life and efficiency of wearable devices but also makes them more adaptable to various forms, such as being incorporated into different wearable accessories.

The researchers are optimistic about the future applications of their work, expecting it to be a key material in next-generation energy storage, including fiber-type batteries that could further enhance device performance.

Dr. Kim Seung-min highlighted the broader potential of carbon nanotube fibers, noting their resurgence as a valuable material for battery technology.

Dr. Jeong emphasized the competitive edge their technology holds internationally, thanks to its originality and effectiveness.

This advance in material science marks a significant step toward more functional and user-friendly wearable technologies, paving the way for devices that are not only smarter but also more integrated into our daily lives.