New stretchable battery may pave the way for smart clothes

Another type of bendable/stretchable polymer battery prototype being developed in the UH lab of Haleh Ardebili. (Reference image by the University of Houston).

University of Houston researchers have developed a successful prototype of a fully stretchable fabric-based lithium-ion battery.

“As a big science fiction fan, I could envision a ‘science-fiction-esque future’ where our clothes are smart, interactive and powered,” lead researcher Haleh Ardebili said in a media statement. “It seemed a natural next step to create and integrate stretchable batteries with stretchable devices and clothing. Imagine folding or bending or stretching your laptop or phone in your pocket. Or using interactive sensors embedded in our clothes that monitor our health.”

According to Ardebili, some of these ideas are already becoming a reality. However, like all electronics, they need power, which is where the stretchable and flexible batteries come in.

The researcher noted that a major bottleneck in the development of the next generation of electronics or wearable technology embedded in fabrics is that conventional batteries are generally rigid, which limits the functionality of the items, and they use a liquid electrolyte, which raises safety concerns. The traditional organic liquid electrolytes are flammable and can lead to the possibility of the batteries catching fire or even exploding under certain conditions.

But the key to her team’s breakthrough lies in their use of conductive silver fabric as a platform and current collector.

“The weaved silver fabric was ideal for this since it mechanically deforms or stretches and still provides electrical conduction pathways necessary for the battery electrode to function well. The battery electrode must allow movement of both electrons and ions,” Ardebili said.

By transforming rigid lithium-ion battery electrodes into wearable, fabric-based, flexible, and stretchable electrodes, this technology opens up possibilities by offering stable performance and safer properties for wearable devices and implantable biosensors.

Smart space suits

The idea for stretchable batteries occurred to Ardebili several years ago.

“I was interested in understanding the fundamental science and mechanisms related to stretching an electrochemical cell and its components,” she said. “This was an unexplored field in science and engineering and a great area to investigate.”

The science of coupling effects of mechanical deformation and electrochemical performance is an important field and stretchable batteries provide a great vehicle for exploring the fundamental mechanisms.

“Although we have created a prototype, we are still working on optimizing the battery design, materials and fabrication,” the scientist said.

Ardebili is optimistic that the prototype for a stretchable fabric-based battery will pave the way for many types of applications such as smart space suits, consumer electronics embedded in garments that monitor people’s health and devices that interact with humans at various levels. There are many possible designs and applications for safe, light, flexible and stretchable batteries, but there is still some work to be done before they are available on the market.

“Commercial viability depends on many factors such as scaling up the manufacturability of the product, cost and other factors,” she said. “We are working toward those considerations and goals as we optimize and enhance our stretchable battery.”