Researchers from University College London, led by Angelos Michaelides, have made a significant discovery about the behavior of water under extreme conditions, with potential implications for energy storage technologies. The team, including Samuel W. Coles, Amir Hajibabaei, Venkat Kapil, Xavier R. Advincula, Christoph Schran, and Stephen J. Cox, has uncovered a new state of water that is both molecular and superionic when confined at the nanoscale.
Superionic ice is a peculiar state of water where molecules dissociate into a lattice of oxygen ions and a highly mobile ‘gas’ of protons. This state is known to exist in the interiors of planets and has been a subject of interest for energy applications. However, the team’s recent findings reveal that water can exhibit superionic behavior while remaining intact as molecules when confined in nanoscale spaces. This is in stark contrast to the behavior of bulk ice, where water molecules dissociate to form a superionic state.
The researchers used machine learning and electronic structure simulations to understand how nanoconfined water can be both molecular and superionic. They found that the exceptional conductivity of this nanoconfined water arises from the activation of the Grotthuss mechanism, a process where protons hop along a network of hydrogen bonds. This mechanism is facilitated by low barriers to proton transfer and a flexible hydrogen-bonded network, two key characteristics that the team proposes are essential for fast ionic conduction in molecular superionics.
The insights gained from this study establish design principles for discovering other molecular superionic materials. These materials could have potential applications in energy storage, such as in advanced batteries and fuel cells, where fast ionic conduction is crucial. The research was published in the journal Nature Communications, offering a new avenue for exploring the fundamental properties of water and developing innovative energy technologies.
In summary, the discovery of nanoconfined superionic water opens up new possibilities for understanding and harnessing the unique properties of water under extreme conditions. The practical applications of this research could lead to advancements in energy storage technologies, contributing to the development of more efficient and sustainable energy solutions.
This article is based on research available at arXiv.