Aquatic Colloidal Graphene Gel Polymer Electrolyte for Flexible Rechargeable Zinc Air Batteries

Abstract

An alkaline gel polymer electrolyte, namely a poly (acrylic acid)-zinc acetate (Zn(AC)2)-aquatic colloidal graphene (ACG) solution (PAA-Zn(AC)2-ACG), was prepared by solution casting method. Properties of PAA-Zn(AC)2-ACG were studied by Fourier transform infrared spectrometer (FTIR), scanning electron microscopy (SEM), AC impedance, cyclic voltammetry (CV) and water retention ability. Results obtained show that PAA-Zn(AC)2-ACG exhibits a high ionic conductivity of 407.9 mS·cm–1, an electrochemical stability window of 1.7 V, and 72.5% water retention ability. Flexible zinc-air batteries (ZABs) with PAA-Zn(AC)2-ACG gel polymer electrolyte have an better discharge capacity of 672 mAh g−1 Zn at 0.5 mA·cm–2 (current density), a continuous charge-discharge duration of 43.3 h, 130 cycles, and a cycle efficiency of 64.8%. Based on work done in this study, it can be concluded that flexible ZABs have advantageous prospects and large potential for practical applications.