Two‐Dimensional Polydopamine Positive Electrodes for High‐Capacity Alkali Metal‐Ion Storage

Abstract

AbstractRedox‐active organic compounds have attracted substantial attention as charge storage materials, owing to their high theoretical capacity. Herein, a two‐dimensional organic electrode material is prepared by using hydrothermally polymerized dopamine molecules on graphene nanosheets. Two‐dimensional polydopamine is employed as a positive electrode for storing alkali metal ions based on the surface redox reaction between oxygen functional groups and alkali ions. The two‐dimensional polydopamine positive electrodes deliver high capacities of 255 mAh g−1 in Li cells, 150 mAh g−1 in Na cells, and 124 mAh g−1 in K cells at 0.1 A g−1, demonstrating a promising organic positive electrode for rechargeable alkali‐ion batteries.