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

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