Battery developed at OSU uses only hydronium ions as charge carrier

Researchers with Oregon State University (OSU) have developed they claim to be the world's first battery to use only hydronium ions as the charge carrier.

Hydronium, also known as H3O+, is a positively charged ion produced when a proton is added to a water molecule. By demonstrating that hydronium ions can be reversibly stored in an electrode material consisting of perylenetetracarboxylic dianhydridem, or PTCDA, researchers in the OSU College of Science have said the new type of battery has shown the promise for sustainable, high-power energy storage.

"This may provide a paradigm-shifting opportunity for more sustainable batteries," said Xiulei Ji, assistant professor of chemistry at OSU and the corresponding author on a paper published in the journal Angewandte Chemie International Edition, a publication of the German Chemical Society. "It doesn't use lithium or sodium or potassium to carry the charge, and just uses acid as the electrolyte. There's a huge natural abundance of acid so it's highly renewable and sustainable."

While PTCDA is an organic, crystalline, molecular solid, the battery created in the Department of Chemistry at OSU uses dilute sulfuric acid as the electrolyte.

Until now, cations, or ions with a positive charge, that have been used in batteries have been alkali metal, alkaline earth metals or aluminum, Ji noted. "No nonmetal cations were being considered seriously for batteries."

The researchers observed a big dilation of the PTCDA lattice structure during intercalation, or the process of its receiving ions between the layers of its structure. That meant the electrode was being charged, and the PTCDA structure expanded, by hydronium ions, rather than extremely tiny protons, which are already used in some batteries. "Organic solids are not typically contemplated as crystalline electrode materials, but many are very crystalline, arranged in a very ordered structure," Ji said. "This PTCDA material has a lot of internal space between its molecule constituents so it provides an opportunity for storing big ions and good capacity."

The hydronium ions migrate through the electrode structure with comparatively low "friction," which translates to high power. "It's not going to power electric cars," Ji was quoted as saying in a news release from OSU on Monday. "But it does provide an opportunity for battery researchers to go in a new direction as they look for new alternatives for energy storage, particularly for stationary grid storage."

Stationary storage refers to batteries in a permanent location that store grid power, including power generated from alternative energy sources such as wind turbines or solar cells, for use on a standby or emergency basis. Endit