Towards High‐Performance Aqueous Zinc Batteries via a Semi‐Conductive Bipolar‐Type Polymer Cathode

Abstract Aqueous Zn‐organic batteries have received considerable attention owing to their green, low‐cost and high safe nature. Unfortunately, organic materials generally exhibit insulator nature (≈10 −10 S cm −1 ), and most of reported promising performances of Zn‐organic batteries are achieved with a low mass‐loading (≈2 mg cm −2 ) in cathode, which is far away from practical application (10 mg cm −2 ). Herein, we demonstrate a semi‐conductive polymer poly(1,8‐diaminonaphthalene) (PDAN) cathode material for Zn batteries, which shows a moderate electronic conductivity (5.9×10 −5 S cm −1 ). Theoretical calculations and in situ/ex situ analysis reveal that the cathode involves a bipolar‐type charge storage mechanism. Accordingly, the Zn//PDAN cell exhibits a promising capacity (140 mAh g −1 at 0.1 A g −1 ) and a remarkable cycle stability (1000 cycles without capacity fading) at a high mass‐loading (10 mg cm −2 ). These encouraging results shed light on the design of advanced organic electrode.