Synthesis Of Catalysts Based On Microfluidic Technology And Studies On The Electrolyte For Zinc–Air Battery

With the continuous development of science and technology.In recent years,a variety of flexible,foldable and wearable electronic device are appearing before our eyes.For the better development of such products and accelerating their industrialization process,it is essential to produce flexible energy storage devices with high energy density,reliability and safety.Among the various energy storage technologies,zinc–air batteries（ZABs）are favorable candidates for upcoming energy storage systems because of their inexpensive materials,environmental friendliness and high theoretical energy density(1086 Wh kg^–1).ZABs are mainly composed of a zinc electrode,an air electrode and electrolyte.The OER and ORR reactions occurring on the air cathode directly affect the charging and discharging performance of ZABs.However,the development of ZABs has been severely constrained by bifunctional catalyst.Most people still use traditional hydrothermal methods to develop high-performance catalysts.The method is time-consuming and laborious in the synthesis process which make the experiment efficiency seriously reduced.In addition,it must prepare a large amount of solution to meet the accuracy requirements of the experiment,thus generating unnecessary waste.Besides,the research on the synthesis of catalysts by high-throughput means is still limited and most of them are very low in automation.Furthermore,the number of samples prepared by different experiments in one experiment is very limited,which cannot satisfy the further pursuit of convenience and efficiency.Electrolytes have been regarded as one of the most important components that greatly affect the performance of ZABs.KOH–PVA electrolyte is widely used in recent research in ZABs.However,severe dendrite and passivation of the zinc anode in ZABs are caused by KOH–PVA electrolyte,which will decrease the cycling performance.However,few people have studied the dendrite and passivation of electrolytes on zinc anodes systematically.In addition,few new electrolyte systems have been proposed to alleviate this phenomenon.In order to develop high-performance bifunctional catalyst for ZABs more efficiently and to improve the water retention property and shelf life of electrolyte.In this paper,we develop a high-throughput material synthesis device with concentration and temperature gradient with high degree of automation based on microfluidic technology at first.Through this device,we synthesized a Co–Fe binary oxide material array with different temperature and concentration parameters and characterized their morphology and composition.In addition,we screened individual sample for amplification experiments to further characterize their composition and electrochemical performance.On the other hand,we use tetraethylammonium hydroxide（TEAOH）to replace KOH as the ionic conductor to synthesize the TEAOH–PVA electrolyte and studied its composition,structure and bond formation in detail.Besides,the effect of both KOH–PVA and TEAOH–PVA on zinc anode were studied.It was concluded that TEAOH–PVA can inhibit the dendrite and passivation of zinc anode and have better cycling life.