Preparation,Modification And Research On Environmental Stability Of Gel Polymer Electrolytes For Flexible Zinc–air Batteries

Due to the depletion of fossil fuels and their inevitable problem of environmental pollution,research on new environmentally friendly flexible energy storage devices has become urgent.Therefore,in recent years,a large number of researches on flexible zinc-air batteries have appeared,aiming to improve the flexibility of zinc-air batteries.In order to overcome the risk of liquid leakage that may occur when flexible zinc-air batteries are bent,alkaline gel polymer electrolyte has attracted the researchers' attention as a new semi-solid electrolyte.KOH–PVA electrolyte is an important part of the alkaline gel polymer electrolyte.Due to its low cost,easy preparation and stable physicochemical properties,KOH–PVA electrolyte has been widely used in zinc-air batteries.However,most of the current researches in the field of flexible zinc-air batteries has focused on the field of catalysts,and there are few studies on the KOH–PVA electrolyte itself.At the same time,as far as we know,KOH–PVA alkaline gel polymer electrolyte exhibits some evident drawbacks,in which poor water retention performance greatly affects discharge performance and working life of flexible zinc-air battery.In this paper,a freestanding KOH–PVA gel polymer electrolyte was prepared and a series of studies were carried out on its water retention performance.On this basis,the KOH–PVA gel polymer electrolyte was modified to prepare a PVA-TEAOH electrolyte.Water content of the new electrolyte was tested after exposure in ambient conditions for different days,and ion conductivity was tested to study the water retention ability of the electrolyte.Factors influencing water retention performance were investigated in the aspect of structure and composition.At the same time,an all-solid flexible zinc-air battery was prepared by using the new electrolyte,and the influence of electrolyte on discharge performance,polarization performance and charge-discharge cycle performance of the battery were investigated.It is found that the water retention performance of the novel alkaline gel polymer electrolyte is much better than that of the KOH–PVA electrolyte,which significantly improves discharge performance and working life of the flexible zinc-air battery.This paper proposes a new PVA-based alkaline gel polymer electrolyte,and provides an idea for the future research of flexible zinc-air batteries.