We’re getting phones with flexible displays, smart-watches with a flexible screen and many other pieces of tech like this. However, what is not truly flexible is the battery powering these devices.
The lithium-ion battery on these devices are rigid and not at all flexible — as they have been in the past. However, researchers have now developed a battery that can flex the way you want it to.
The battery tech is developed by a team of researchers at ETH. Now you might be wondering how is this possible, as lithium-ion batteries are known to catch fire the moment they’re flexed or tampered with. However, researchers have been able to achieve this feat by the discovery of an entirely new electrolyte.
The battery is built-in layers like a sandwich. And the layers are using flexible components that are an industry-first. The collectors for anode and cathode are made of a bendable polymer composite that consists of electrically conductive carbon. This is also the outer shell of the battery.
On the inside, the scientists have included a thin layer of micronised silver flakes. The flakes overlap like roof tiles, thus always maintaining contact, even when the polymer is being stretched or in unusual angles. And if it was to reach a point where it is not able to make contact, the current will still travel through the carbon-composite, obviously a little more weakly than the inner layer.
Scientists have sprayed anode and cathode powder on a specific area on the silver layer. The cathode is made of lithium manganese oxide whereas the anode is made with vanadium oxide.
However, the star of this setup is the electrolyte gel that is filled in the gap between the electrodes. According to Niederberger M, Professor for Multifunctional Materials at ETH Zurich, the electrolytes are environmentally more friendly than the ones commercially used in batteries today.
Developed by doctoral student Chen X, the electrolyte contains water with a high concentration of lithium salt that aids not just in conductivity but also helps water to not be affected by electrochemical decomposition (general wear and tear of electrochemical in the battery).
While the entire prototype is sealed shut with adhesive, according to Niederberger, “If we want to market the battery commercially, we’ll have to find another process that will keep it sealed tight for a longer period of time.”
Such batteries could be helpful in smart clothing which could have trackers for close health monitoring along with future flexible smartphones and smart watches, while also paving the way for more innovation in the flexible-gadgets space.