Optimizing Layered and 2D Materials as Ion Intercalation Electrodes towards High Power Electrochemical Energy Storage
Current state-of-the-art lithium-ion batteries (LIBs) contain electrode materials with mostly layered structures that serve as host lattices for the reversible, electrochemical intercalation of lithium ions. The kinetics of these intercalation reactions are typically limited by the solid-state diffusion of the ions inside the lattice. Volumetric changes that accompany the (de-)insertion of ions further lead to degradation of the electrode materials. These factors contribute to the limited power and lifetime of LIBs. While some of these limitations can be mitigated by nanostructuring of the electrode material, there is a large interest in finding structural motifs that allow for intrinsically fast ion diffusion with reduced host lattice deformation, even in bulk-sized particles.
In this presentation, I will highlight how interlayer properties, such as interlayer distance and interlayer chemistry, affect electrochemical ion intercalation processes in layered host materials. It is demonstrated that the presence of interlayer structural molecules can increase the accessibility of intercalating ions to the interlayer space and affect their transport properties. Increased interlayer spacing and reduced deformation during ion intercalation can lead to a change from diffusion-limited to non-diffusion limited (or pseudocapacitive) charge storage behavior, enabling favorable charge storage kinetics.
The talk will give an overview of my research group’s efforts to synthesize interlayer-functionalized layered and two-dimensional materials with tailored interlayer properties towards high power intercalation electrodes and highlight the challenges regarding both materials synthesis and characterization.