An Ultrahigh Output Rechargeable Electrode of a Hydrophilic Radical Polymer/Nanocarbon Hybrid with an Exceptionally Large Current Density beyond 1 A cm⁻²

Abstract Facile charge transport by a hydrophilic organic radical‐substituted polymer and the 3D current collection by a self‐assembled mesh of single‐walled carbon nanotube bundles lead to the operation of an ultrahigh‐output rechargeable electrode. Exceptionally large current density beyond 1 A cm⁻² and high areal capacity around 3 mAh cm⁻² are achieved, which are 10¹⁻² times larger than those of the previously reported so‐called “ultrafast electrodes.” A sub‐millimeter‐thick, flexible, highly safe organic redox polymer‐based rechargeable device with an aqueous sodium chloride electrolyte is fabricated to demonstrate the superior performance.