Study On Sulfur Iron And All-iron Electrolyte Flow Battery In Eutectic Solvent

Compared with traditional energy storage battery cells,redox flow battery as a large-scale energy storage technology has the advantages of high capacity,large energy storage and long cycle life.It is a new type of large-capacity electrochemical energy storage device actively researched and developed.Its active material is a flowing electrolyte solution,which meets the following requirements: 1.The electrode potential difference between the positive and negative oxide redox couples is large,and the redox is redox.The electric pair has good reversibility.3.It is easy to prepare,has good stability and low price.Deep eutectic solvent(DES)is a very promising electrolyte for non-aqueous redox flow batteries with easy preparation,wide electrochemical window,low vapor pressure,excellent solubility and conductivity,non-toxic,biodegradable and other advantages and features.And has been widely used in the field of electrochemistry,but also in line with the concept of green technology,green chemistry.Fe(II)/Fe(III)has the advantages of no pollution and low cost,but the standard electrode potential is only 0.77 V.Therefore,we add a complexing agent to make Fe(II)/Fe(III)redox couple in DES.The intermediate potential shifts and enhances the reversibility of the reaction.The S42-/S8、[Fe Cl4]-/[Fe Cl4]2-and [Fe(TEOA)OH]-/ [Fe(TEOA)OH]2-pairs are positive and negative electrolytes respectively,and AMI-7001 is an anion exchange membrane combined into a battery and a liquid.Flow battery,electrochemical test,battery voltage efficiency,current efficiency,battery efficiency.In this paper,a combination of a deep eutectic solvent as a solvent,an iron complex and a polysulfide ion as an electrolyte,an AMI-7001 as an anion exchange membrane,and a reduced graphene oxide and gold nanoparticle-activated carbon paper electrode to form a battery and a flow battery The electrochemical test was performed on the assembled battery.This article focuses on the following points:(1)Reversibility of[Fe Cl4]-/[Fe Cl4]2-pair,[Fe(TEOA)OH]-/ [Fe(TEOA)OH]2-pair,and S42-/S8 pair on different electrodes by cyclic voltammetry the study.(2)The carbon paper electrode was activated by cyclic voltammetry and chronoamperometry: ERGO-carbon paper electrode was prepared by reducing graphene oxide on carbon paper,and gold nanoparticle was reduced on carbon paper to prepare Au-carbon paper electrode.And test the catalytic effect of the electrode in the electrolyte.(3)Using the prepared electrode and electrolyte to form a battery and a flow battery,the charge and discharge performance of the battery was tested by a chronopotentiometry method.The activated carbon paper electrode exhibits good reversibility and small potential difference in the complex electrolyte compared to the unactivated carbon paper electrode.The combined flow battery exhibits high storage stability and good stability.