Enabling Storage of Divalent Cations in Layered Vanadium Pentoxide through Controlled Interlayer Interactions

Abstract

Cathode materials that store divalent cations (Mg2+, Zn2+, Ca2+) can provide batteries with high capacities, lower costs, and improved safety. However obtaining cathode materials that store divalent cations and have high voltages, high capacities, and high reversbilities remains a key challenge due to the high charge densities and polarizabilities of divalent cations which results in strong interactions with the host lattice and low diffusion coefficients. Our group has investigated layered vanadium pentoxide (V2O5) as a model host material for divalent cation charge storage. Recent work by our group has shown that incorporation of poly(ethylene oxide) between the V2O5 layers alters the interlayer structure and dynamics and improves the transport and storage of divalent Mg2+.1 Based on the importance of the characterizing the structure of the interlayer region, we have used changes in Raman-active acoutic phonon modes to probe interaction of solvents and ions with the V2O5 layers. The effects of altering polymer composition within the interlayer and the electrolyte composition on the storage of divalent cations have been recently explored, and results of this work will be presented. The design of layered materials with controlled interlayer compositions provides an approach to significantly improve charge storage and transport of divalent cations. References Perera, S.D.; Archer, R.; Damin, C.A.; Mendoza-Cruz, R.; Rhodes, C.P. Controlling interlayer interactions in vanadium pentoxide-poly(ethylene oxide) nanocomposites for enhanced magnesium-ion charge transport and storage, Journal of Power Sources, 2017, 343, 580-591. DOI:10.1016/j.jpowsour.2017.01.052.