Gel polymer electrolyte with alkaline aquatic colloidal graphene for flexible and rechargeable zinc air batteries

Abstract

The alkaline gel polymer electrolyte, polyvinyl alcohol (PVA)-sodium polyacrylate (PANa)-aquatic colloidal graphene (ACG)-KI (PVA-PANa-ACG-KI), was prepared by solution casting method. Fourier transform infrared spectrometer (FTIR), scanning electron microscope (SEM), electrochemical impedance spectra (EIS), cyclic voltammetry (CV) and water retention were used to study the performance of PVA-PANa-ACG-KI gel polymer electrolyte. The results show that the ionic conductivity of PVA-PANa-ACG-KI is 283.7 mS·cm^–1, the electrochemical stability window is 2.6 V, and the water retention is 73.4%. The discharge capacity of the flexible zinc air batteries (ZABs) with PVA-PANa-ACG-KI gel polymer electrolyte is 803.56 mAh g_Zn^–1, the continuous charge-discharge time is 62 h, the cycle efficiency is 74.2%, and the self-discharge rate is 0.36%. After the charge-discharge cycle, the GPE is recycled and put into use again, which effectively reduces the cost. Finally, the advantages and prospects of flexible ZABs are demonstrated, and the feasibility of flexible ZABs is proved.