What just happened? Researchers from ETH Zurich in Switzerland have developed a flexible thin-film battery that can be bent, stretched and twisted without disrupting its flow of power. That’s in stark contrast to modern lithium-ion batteries which present a major safety risk when flexed.
A key innovation of the flexible battery involves the current collectors for the anode and cathode. They’re made from a bendable polymer composite that contains electrically conductive carbon that is coated with a thin layer of micron-sized silver flakes on the inside. The flakes overlap like roof tiles so when they are stretched, they still remain in contact with each other.
In the event they are stretched too far, electrical current can still flow through the composite thanks to the carbon, albeit not as strong.
Another essential component of the prototype battery is a gel electrolyte that is said to be much safer than commercial electrolytes. ““Liquid electrolytes in today’s batteries are flammable and toxic,” said Markus Niederberger, professor for multifunctional materials at ETH Zurich. It’s important to the team that in the event of leakage, the material that comes out of their battery causes no damage.
As is often the case with battery advances, this one still has a ways to go before it’s ready for commercialization. The team said it needs to come up with a better way to hold the components together so they stay sealed for longer. They also want to be able to include more electrode material.
Shortcomings aside, the malleable battery has several real-world applications. In addition to flexible electronics, such batteries could also be sewn directly into textiles for smart clothing.