protons – Lightsources.org

Researchers from the University of New South Wales (UNSW) have developed a new type of rechargeable battery that uses protons (H⁺ ions) as charge carriers, offering a safer and more environmentally friendly alternative to conventional lithium-ion batteries.

Unlike traditional batteries that rely on metal ions, such as lithium or sodium, this innovative design harnesses protons for fast charge transfer and exceptional stability over thousands of cycles.

The researcher team led by Professor Chuan Zhao at UNSW’s School of Chemistry reported in the prestigious journal Angewandte Chemie the development of a novel small organic molecule called tetraamino-benzoquinone (TABQ), as a cathode material in this proton battery. Developed by PhD candidate Sicheng Wu and Professor Zhao, this TABQ molecules plays a crucial role in storing and transporting protons, leading to remarkable performance and long-term stability.

“Using this TABQ cathode material, we successfully built an all-organic proton battery that performs efficiently at both room temperature and sub-zero freezing temperatures,” said Professor Zhao in a media statement.

A key aspect of the research involved real-time monitoring of chemical changes during battery operation, achieved through advanced synchrotron infrared measurements. Dr Pimm Vongsvivut, Senior Scientist at the Australian Synchrotron’s Infrared Microspectroscopy (IRM) beamline, collaborated with this UNSW team to develop a custom in-situ electrochemical cell and monitoring technique.

“Through this collaboration, we designed a tailored electrochemical cell and an in-situ monitoring approach to track chemical changes during charging and discharging cycles. Our synchrotron infrared technique provided direct chemical evidence confirming that the energy storage mechanism of TABQ relies on a reversible carboxyl/hydroxyl conversion driven by proton uptake and release during cycling,” said Dr Vongsvivut.

The study also revealed that intercalated protons (or hydronium ions) can protonate amino groups, contributing to an intermolecular hydrogen-bond network that enhances the battery’s performance. Computational analysis confirmed that protons are more easily stored in TABQ compared to metal ions, reinforcing the efficiency of this organic system.

Read more on ANSTO website

Image: Professor Chuan Zhao holds up a prototype of a proton battery in the lab, made in collaboration with UNSW Engineering and ANSTO.

Credit: Prof Zhao and UNSW

How hydrogen ions or protons interact with their aqueous environment has great practical relevance, whether in fuel cell technology or in the life sciences. Now, a large international consortium at the X-ray source BESSY II has investigated this question experimentally in detail and discovered new phenomena. For example, the presence of a proton changes the electronic structure of the three innermost water molecules, but also has an effect via a long-range field on a hydrate shell of five other water molecules.

Excess protons in water are complex quantum objects with strong interactions with the dynamic hydrogen bond network of the liquid. These interactions are surprisingly difficult to study. Yet so-called proton hydration plays a central role in energy transport in hydrogen fuel cells and in signal transduction in transmembrane proteins. While the geometries and stoichiometries have been extensively studied both in experiments and in theory, the electronic structure of these specific hydrated proton complexes remains a mystery.

A large collaboration of groups from the Max Born Institute, the University of Hamburg, Stockholm University, Ben Gurion University and Uppsala University has now gained new insights into the electronic structure of hydrated proton complexes in solution.

Using the novel flatjet technology, they performed X-ray spectroscopic measurements at BESSY II and combined them with infrared spectral analysis and calculations. This allowed them to distinguish between two main effects: Local orbital interactions determine the covalent bond between the proton and neighbouring water molecules, while orbital energy shifts measure the strength of the proton’s extended electric field.

Read more on the HZB website

Image: The spectral fingerprints of water molecules could be studied at BESSY II. The result: the electronic structure of the three innermost water molecules in an H₇O₃⁺ complex is drastically changed by the proton. In addition, the first hydrate shell of five other water molecules around this inner complex also changes, which the proton perceives via its long-range electric field.

Tag: protons

A breakthrough in all-organic proton batteries for safer, sustainable energy storage

Influence of protons on water molecules