Advancing energy-storage technologies relies on a fundamental understanding of microscopic material behaviour. Macroscopic performance in functional energy materials is governed by the interplay between charges, lattice vibrations, and light. Understanding these dynamics, particularly how electrons localise or how structural distortions affect ion mobility, is essential for advancing beyond trial-and-error material design.
In this talk, I will present recent work using quantitative optical and spectroscopic methods to track non-equilibrium charge transport in two systems: a cathode material and a solid electrolyte.
First, I will discuss the spatiotemporal dynamics of energy carriers in Li_xMn₂O₄ cathodes. Using a multimodal optical approach, we monitor the formation, relaxation, and diffusion of small polarons, particularly near x≈1, where a phase transition limits Li-rich cathode performance. This methodology isolates the propagation of electronic and thermal energy carriers, disentangling their respective contributions as a function of lithium content.
The second part will address phonon-driven ionic diffusion in the solid electrolyte LLZO. Moving beyond the phenomenological observation of light-enhanced conductivity, this joint theoretical and experimental effort aims to map ion diffusion pathways directly to their contributing vibrational modes and clarify how targeted vibrational excitation can influence macroscopic ion transport.
Taken together, these correlative multimodal approaches provide new insight into coupled electronic and structural dynamics, and help pave the way for the rational design of future energy storage systems.