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

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  S cm ), and most of reported promising performances of Zn-organic batteries are achieved with a low mass-loading (≈2 mg cm ) in cathode, which is far away from practical application (10 mg cm ). 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  S cm ). 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 at 0.1 A g ) and a remarkable cycle stability (1000 cycles without capacity fading) at a high mass-loading (10 mg cm ). These encouraging results shed light on the design of advanced organic electrode.