Self‐Assembled Surfactant‐Polyoxovanadate Soft Materials as Tuneable Vanadium Oxide Cathode Precursors for Lithium‐Ion Batteries

Abstract

AbstractThe mixing of [V10O28]6− decavanadate anions with a dicationic gemini surfactant (gem) leads to the spontaneous self‐assembly of surfactant‐templated nanostructured arrays of decavanadate clusters. Calcination of the material under air yields highly crystalline, sponge‐like V2O5 (gem‐V2O5). In contrast, calcination of the amorphous tetrabutylammonium decavanadate allows isolation of a more agglomerated V2O5 consisting of very small crystallites (TBA‐V2O5). Electrochemical analysis of the materials’ performance as lithium‐ion intercalation electrodes highlights the role of morphology in cathode performance. The large crystallites and long‐range microstructure of the gem‐V2O5 cathode deliver higher initial capacity and superior capacity retention than TBA‐V2O5. The smaller crystallite size and higher surface area of TBA‐V2O5 allow faster lithium insertion and superior rate performance to gem‐V2O5.