An Aqueous, Electrolyte‐Type, Rechargeable Device Utilizing a Hydrophilic Radical Polymer‐Cathode

A hydrophilic poly(vinyl ether)‐backbone polymer bearing a pendant TEMPO radical, poly(2,2,6,6‐tetramethylpiperidinyloxy‐4‐yl vinyl ether) (PTVE), was designed as a cathode‐active material, which displays a reversible one‐electron redox capability, even in an aqueous electrolyte. The PTVE layer coated on a current collector demonstrated a rapid charging‐discharging rate based on the combination of the redox‐active nitroxide radicals built into the hydrophilic polymer and the aqueous electrolyte that possessed a high electrical conductivity. A test cell fabricated with a PTVE cathode, a zinc anode, and an aqueous electrolyte gave an output voltage of 1.7 V and showed the ability to be recharged more than 500 times rechargeability. magnified image