A flexible battery has been developed by researchers from the University of California, Los Angeles, which can withstand being run over by a car, blows from a hammer and temperatures as low as −77°C (-106.6°F). Traditional batteries are solid and based on lithium, but can easily be damaged in an accident, and struggle with extreme temperatures. The hydrogel battery uses a special polymer known as polyvinyl alcohol to make it flexible and durable. The team believe it could potentially be used for electronics such as wearable devices or smartphones.
To make the hydrogel battery, the team combined electrolytes with hydrogels. The electrolyte made the hydrogel conductive, and the polymer made the battery flexible. The device was tested in a range of extreme situations, including being hit with a hammer and having a nail driven into it. Remarkably, the battery continued to work. “We thought that electrochemical performance is going to be much worse after all of these mechanical strikes,” said He. “But we just found out that it turned out to be excellent.”
The hydrogel battery is still in the early stages of development, and the researchers are now focused on increasing the battery capacity. However, once developed, He believes that the flexible battery could be used in a range of other areas, including medical devices such as implantable bioelectronics. These could include devices which monitor the heart or brain, and need to move with the body.
Other potential uses of the hydrogel battery include energy storage for soft robotics, wearable technology, and electric vehicles. The battery could also be used in harsh conditions, such as extreme temperatures which are outside the range of regular lithium batteries. The team also believes that the technology could be used in flexible electronics, an area which has long been coveted by manufacturers.
Currently, the capacity of the hydrogel battery is relatively low compared to other batteries. However, the team is optimistic that the battery technology can be improved, making it practical for commercial use. The researchers will next focus on increasing energy density and testing how the batteries respond in different temperatures and environments. It may be some time until the full potential of the hydrogel battery is realised, but the early results show that it could be a significant step forward for the electronics industry.