Environmentally Friendly and Flexible Aqueous Zinc Ion Batteries Using an Organic Anode and Activated Carbon as the Cathode

We report an outstanding rate capability of a synthesized polymer, poly(3,4,9,10-perylentetracarboxylic diimide) (PPTCDI), as an anode with activated carbon (AC) as a cathode. The cell PPTCDI||AC shows the highest energy density of 174.3 Wh kg–1. The electrode PPTCDI provides a superior rate capability of 199.1 mAh g–1 at a 50 mA g–1 current density. A flexible zinc-ion battery is assembled for the first time using AC and PPTCDI in an aqueous ZnSO4 electrolyte, exhibiting a capacity retention of 95% after 5000 cycles. This work ascertains the feasibility of Zn-ion energy storage and provides a new idea for aqueous battery systems.