Operando Dynamical Studies of Dynamics within Intercalated 2D Materials

I will describe two recent efforts probing the dynamics of ion transport and ion-induced metastable phases as probed by time-resolved optical, x-ray and electron scattering. In Li-intercalated WTe2, we find a new metastable phase featuring an anomalously large in-plane chemical expansion coefficient (expansion per unit lithium inserted). It is common for 2D materials to expand in the out-of-plane direction upon intercalation, but large tunable uniaxial in-plane expansion is much more rare. The unusual actuation of LixWTe2 is linked to the formation of a metastable crystallographic phase, potentially enabling novel means for strain modulation at high frequencies. In the second part of the talk I will describe recent efforts to visualize the dynamics of ion hopping in superionic materials.