Fuel cells can have a hope of improvement due to a discovery by TU Delft researchers in Holland. They added minuscule titanium dioxide crystals to solid electrolytes to make them more conductive. Unlike liquid electrolytes, solid ones have the advantage of being more stable and easier to be contained. Electrolytes are also used mainly in batteries, between their two electrodes.
“In a solid matter you have a network of ions, in which virtually every position in the network is taken. This makes it difficult for the charged particles (protons) to move from one electrode to another. I’s a bit like a traffic jam on a motorway. What you need to do is to create free spaces in the network,” says PhD student Lucas Haverkate.
The titanium dioxide nanoparticles are 7 to 50 nanometers in size, and their role is to attract protons, which creates more space in the ion network. A solid acid accompanies the TiO2 nanocrystals, CsHSO4, and helps them bind to the protons. “The addition of the crystals appears to cause an enormous leap in the conductive capacity, up to a factor of 100,” Haverkate claims.
Wing Kee Chan, Haverkate’s colleague, has been measuring the new TiO2-treated electrolyte by sending neutrons through it, a method called “neutron diffraction.” The neutrons’ dispersion gives the scientists clues about the proton density inside the crystals and other parameters. Haverkate said that measurements such as this one had not been made before, especially at this small scale. They used equipment from the Reactor Institute Delft.
Fuel cells could benefit these electrolyte types (they can also be made with other crystal combinations that they will research in the future) by having larger temperature ranges. One issue that hydrogen fuel cells face today is the special materials needed to be created in order to withstand the high temperatures occurring during the electricity production process.