Liquid Metal Could Soon Power Your Wearable

Battery tech is evolving fast

Key Takeaways

  • Scientists have created a device that might one day eliminate the need for a separate battery in wearables. 
  • The invention is a soft and stretchable device that converts movement into electricity and can work in wet environments. 
  • Researchers are racing to find new ways to power personal electronics.
Someone working out while looking at a wearable on their wrist.

Guido Mieth / Getty Images

Your next wearable device might not need a separate power source, thanks to recent advancements in battery science. 

Researchers have created a soft and stretchable device that converts movement into electricity and can work in wet environments. The invention holds promise for powering wearable devices, charging them spontaneously with no need for an external power source. It's part of a growing effort to find new ways to power personal electronics. 

"The predominant batteries for personal electronics are lithium-ion batteries, which have been the best rechargeable batteries for about thirty years," Bingqing Wei, the director of the Center for Fuel Cells and Batteries at the University of Delaware, told Lifewire in an email interview. Wei was not involved in the new research. 

"However, today's Li-ion batteries suffer from safety problems and limited capacity," Wei added.

Stretchy Charging

North Carolina State University scientists hope their new invention could tackle some of the limitations of current battery tech. The heart of the energy harvester they created is a liquid metal alloy of gallium and indium. The alloy is encased in a hydrogel—a soft, elastic polymer swollen with water, according to a recently published paper

"Mechanical energy—such as the kinetic energy of wind, waves, body movement, and vibrations from motors—is abundant," Michael Dickey, one of the paper's authors, said in a news release. "We have created a device that can turn this type of mechanical motion into electricity. And one of its remarkable attributes is that it works perfectly well underwater."

The researchers are working on another project to power wearable devices by increasing the harvester's power output.

Battery Innovations

Researchers worldwide are racing to find new ways to power electronics, Chibueze Amanchukwu, a professor of molecular engineering at the University of Chicago, told Lifewire in an email interview. One approach is to boost the energy density of batteries to increase battery life. 

"These projects focus on replacing graphite in the battery with silicon and lithium metal," Amanchukwu said. "To address the safety concerns, researchers like me are interested in completely replacing the flammable and dangerous liquids in the battery with nonflammable solid-state versions."

Innovations in battery technology could result in new and improved personal electronics that are not possible today, Amanchukwu said. 

"Devices would become safer and last far longer, meaning they can play or work more," he added. "Flexible batteries would also allow wearable personal devices that conform better to the body (think of a truly flexible Apple Watch) and can power 'smart clothes' and smart IoT devices."

A battery charging display.

artpartner-images / Getty Images

The key to new battery technologies is all about getting better performance out of the same-sized unit, Amionx CEO Jenna King told Lifewire in an email interview. 

"This is why we see so many companies focused on improving the safety of these batteries as well," King added. "In essence, the battery becomes a more powerful bomb in the same package."

Better Batteries for a Better Future

A new type of battery using nano silicon materials replaces the typical anode (negative electrode) material in lithium-ion batteries. 

"This allows for a much more powerful battery, but it also means the battery poses a bigger safety risk," King said. "There are also advancements in rechargeable lithium metal batteries which also increase energy density. The industry is attempting to overcome issues with cycle life in these batteries as well as the chance for fires or explosions."

Future battery technology could help tackle climate change issues, Francis Wang, the CEO of NanoGraf Technologies, an advanced battery material startup, told Lifewire in an email interview. 

"Better batteries will enable greater and faster adoption of electric vehicles, as performance and price points meet mainstream consumer demands," Wang added. "Improved batteries also will usher in a new era of grid-scale energy density where batteries will help balance the grid and support lower emissions."

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