Interface-mediated fast ionic conductivity in nanocomposite solid-state electrolytes

Descripción del proyecto

Las bases para el futuro de los electrolitos en estado sólido

Las baterías modernas, las pilas de combustible y otros dispositivos electroquímicos dependen en gran medida de la conducción de iones en electrolitos en estado sólido (EES). Sin embargo, el desarrollo de estos dispositivos se ha visto limitado durante mucho tiempo por la baja conductividad intrínseca de los EES. Ello ha espoleado los trabajos centrados en mejorar la conductividad de los ESS. Si bien la investigación ha demostrado que los no conductores pueden afectar de forma sustancial a la conductividad de los ESS, los esfuerzos por mejorarla no han tenido éxito. El proyecto Interfacial Ionics, financiado por el Consejo Europeo de Investigación, tiene como objetivo estudiar y dilucidar los mecanismos básicos que subyacen a la conductividad iónica de la interfaz, lo que posibilitará el desarrollo de EES a medida con mezclas de óxidos. El equipo del proyecto estudiará modelos de EES nanocompuestos con óxidos y empleará diversas técnicas de ensayo para analizar las composiciones de las interfaces y otros factores clave.

Objetivo

Ion conduction in solid-state electrolytes (SSEs) is the bedrock of several electrochemical devices like batteries and fuel cells which are vital to our modern society. High conductivity is crucial for such applications, and increasing the intrinsically low conductivity of SSEs has been of enormous technological interest. The discovery that the conductivity of SSEs can increase or decrease by orders of magnitude at their interface with a non-conductor (e.g. oxides) has led to much interest in the use of interface engineering to rationally design SSEs with improved conductivity and overall performance in electrochemical devices. This has so far not been successful because the underlying mechanisms that lead to the profound changes in conductivity at interfaces are not yet well understood due to the complex composition of such interfaces, and the fact that several properties of the two components concomitantly influence this effect.

Building on my preliminary results, I aim to unravel the fundamental mechanisms of interface ion conductivity by preparing model nanocomposite SSEs (SSE + oxides) that will allow me to disentangle the different parameters that contribute to this effect. The interface physics/chemistry responsible for interface ion transport will be precisely tuned via surface and compositional modification of the oxides. I will combine advanced surface-sensitive probe techniques, including XPS, X-ray Raman Scattering, HR-TEM/EDX, and NMR to study the interface compositions. This will enable me to establish for the first time how the properties of SSE-oxide mixtures influence their interface reactions, conductivity, and performance in applications. Such fundamental insights will enable the design of novel SSEs with tailor-made properties for a variety of electrochemical applications. My extensive expertise and track record in nanocomposite materials, SSEs, and advanced materials characterization, place me in the perfect position to lead this project.