In the realm of energy research, understanding the behavior of materials at the atomic level can lead to significant improvements in energy storage and conversion technologies. A recent study by Jörg Weissmüller, a researcher at the Technical University of Berlin, delves into the fundamental physics governing the transfer of particles across interfaces in solid materials, with potential implications for the energy sector.
The research, published in the journal Physical Review Letters, focuses on the thermally activated transfer of solute particles across the interface between two interstitial solid solution phases. These phases are in equilibrium internally, meaning that particles can move quickly within each phase due to fast diffusion on conserved arrays of sites. The study uses statistical mechanics to predict how particles occupy transition states at equilibrium, which depends on the barrier energy and the chemical potentials and vacancy fractions in each phase.
Weissmüller’s work derives a rate law for the non-equilibrium interfacial transfer, assuming a constant transition probability between activated states. This rate law naturally satisfies the principle of detailed balance, a fundamental concept in statistical mechanics that ensures equilibrium is maintained. Unlike traditional Butler-Volmer-type laws, which are commonly used to describe electrochemical reactions, the new rate law explicitly includes the chemical potentials of the particles rather than just their differences. Additionally, it takes into account the vacancy fractions in each phase, leading to an exchange flux density that depends on the compositions at equilibrium.
One of the practical applications of this research is in the field of metal hydrides, which are used for hydrogen storage. The study’s findings can explain experimental observations of a significant slow-down in the charging of metal hydrides near phase transformations or miscibility-gap critical points. This understanding could lead to the development of more efficient hydrogen storage materials, which are crucial for the advancement of clean energy technologies.
In summary, Weissmüller’s research provides a deeper insight into the fundamental processes governing particle transfer in solid materials. By understanding these processes, researchers can develop better materials for energy storage and conversion, ultimately contributing to a more sustainable energy future. The study was published in Physical Review Letters, a prestigious journal in the field of physics.
This article is based on research available at arXiv.