\Achieving high capacity and long life of aqueous rechargeable zinc battery by using nanoporous-carbon-supported poly(1,5-naphthalenediamine) nanorods as cathode

Aqueous rechargeable Zn-ion batteries (ZIBs) are safe, low cost, and environmentally friendly, yet the realization of both high capacity and long cycling life remains a major challenge. Herein, electrodeposited poly(1,5-naphthalenediamine) nanorods over nanoporous carbon are used as the cathode material to make aqueous ZIBs that can be operated within the voltage range of 0.1 - 1.8 V and have merits of both ionic battery and supercapacitor. Flexible carbon fiber fabric and thick carbon fiber felt are used as current collectors, respectively, to support the polymer/carbon composite with different mass loadings. With using the carbon fabric, flat pouch cells and cable-shaped micro cells are fabricated and show stable electrochemical performances when repeatedly bent at large angles. The pouch cells show maximum energy and power densities of 195 Wh kg(-1) and 104 W kg -1, respectively, and achieve a capacity retention of 91% after 10000 cycles. The prototype cell with using a 3 mmthick carbon felt shows higher energy densities up to 7.7 mWh cm(-2) and better cycling stability, i.e., 100% capacity retention after 10000 cycles. Also, insights into the charge storage mechanism and superb cycling stability of our new polymer cathode are given.