Researchers at the UK’s University of Surrey have designed a prototype battery that keeps smart wearables charged with only a few seconds of sunlight.

Thirty seconds of sunlight could boost the battery life of future smartwatches and other wearables by tens of minutes, thanks to the renewable and rechargeable battery prototype developed by the university’s Advanced Technology Institute (ATI).

The photo-rechargeable system merges zinc-ion batteries with perovskite solar cells and could allow wearables to spring back to life without the need to plug in.

“This technology provides a promising strategy for efficient use of clean energy and enables wearable electronics to be operated continuously without plug-in charging,” said Jinxin Bi, a PhD candidate at ATI and the first author of the paper. “Our prototype could represent a step forward to how we interact with wearables and other internet-of-things devices, such as remote real-time health monitors.”

The environmentally friendly, photo-rechargeable system is unique because of its elegant and well-matched structural design between the integrated battery and solar cell, allowing it to demonstrate high energy and volume density comparable to the latest micro-batteries and supercapacitors.

“This project is an example of how the University of Surrey is dedicated to producing research and innovation that equips humanity with the knowledge, tools and technologies to help us live better and more sustainable lives,” said Wei Zhang, project co-lead and expert in perovskite solar cells.

Yunlong Zhao, project co-lead and expert in batteries for wearables and implantables, added: “The unique features in our ultrafast photo-rechargeable system could promote wide applications in self-powered wearable internet-of-things, autonomous power systems and emergency electronics. In addition, it will broaden the perception and insight of designing the next generation of miniaturised flexible photo-rechargeable systems.”

The research was published in Energy Storage Materials.