Study Of Neutral Gel Polymer Electrolytes For Flexible Zinc–air Batteries

The rapid advancement of wearable and biocompatible electronic devices including flexible electronics,wearable displays,and artificial skin sensor have created an urgent demand for flexible,lightweight and nontoxic energy storage devices.Flexible zinc–air batteries(ZABs)have been regarded as a promising alternative due to their extremely high theoretical energy density(1086 Wh·kg^–1),intrinsic safety,low cost,and environmental friendliness.Conventional flexible ZABs mainly use alkaline electrolyte,which has some disadvantages.First,Zn anode suffers from severe corrosion problems resulting in the deterioration of Zn anode;Secondly,the fast carbonate formation of the electrolyte associated with the reactions of OH^–and CO₂ in air results in the decrease of ionic conductivity of the electrolyte;Moreover,the C in carbon-based air cathode can react with the OH^–in the alkaline electrolyte,which results in the deterioration of air cathode.In addition,ZABs possess a unique half-open system in which the air cathode is open to the air,resulting in the water loss in the electrolyte from one side of the air cathode.Therefore,the water retention capacity of the electrolyte needs to be improved to improve the battery performance.The above-mentioned problems affect the battery performance(e.g.,storage life and cycling life),especially for storage life which has an important impact on the practical application.It is important to explore the storage life and key factors that determine the storage life of ZABs.Herein,on the one hand,we studied the storage life of alkaline gel electrolyte based ZABs and explored the key factors that determine the storage life.Then a neutral gel polymer electrolyte composed of PVA and a chlorine-based solution was prepared and first reported,which exhibits excellent water retention capacity and high carbonation resistance and highly stable environment for zinc electrodes.The neutral gel polymer electrolyte prolonged the storage life and cycling life of ZABs.On the other hand,a neutral gel polymer electrolyte composed of Si O₂ was prepared to improve the mechanical properties and water retention capacity of the electrolyte.In addition,the development direction and application prospect of the neutral gel polymer electrolyte based flexible ZABs are prospected.As far as we know,there are few literatures on the detailed research on the neutral gel polymer electrolyte of flexible ZABs.This paper provides new ideas for the future development of flexible ZABs.