Study On The Performance Of Anode Single-Flow Zinc-Nickel Battery For Building Energy Storage

In recent years,the application of photovoltaic power generation in building energy saving is more and more extensive,but the output power of photovoltaic power generation changes with the change of meteorological conditions,and it is intermittent.In order to ensure the continuous power supply to the load,the energy storage system must be installed.Energy storage technology ensures that the power system can provide people with continuous and stable power support.Liquid flow battery,as an energy storage device in the building,is cheap and reliable,with large energy storage capacity,multiple cycles and long service life.It can be used for energy conversion and storage efficiently,and can also be used as a peak shaving energy storage device in the power grid.However,problems such as zinc dendrite,zinc passivation,corrosion and zinc deformation often accompany the cycle of flow batteries,resulting in capacity loss and battery performance degradation.So far,many attempts have been made to improve the performance of zinc negative electrodes,including the use of additives in electrodes or electrolytes.Although the cycle life and performance of zinc electrodes have been improved to some extent,the problem is still difficult to solve.In order to improve the performance of the negative electrode of zinc-nickel single-flow battery,the phase analysis,cyclic voltammetry?CV?and galvanostatic charge-discharge tests were carried out by means of SEM and EDS techniques,focusing on the improvement of the performance of the negative electrode of single-flow zinc-nickel battery,including deposition morphology,Coulomb efficiency,self-corrosion and hydrogen evolution.The effects of different anode substrates on the deposition/dissolution behavior of zinc in the base solution were studied experimentally.On the premise of determining the anode substrates,the self-corrosion of zinc in the deposition and dissolution process was further inhibited by optimizing the electrolyte,and the overall charge-holding capacity of the battery was improved.The study found that:1.By comparing the effects of different anode substrates on the deposition/dissolution behavior of zinc in the basic solution,it was found that nickel-plated steel strip was more suitable for the negative collector of zinc-nickel single-flow batteries than other substrates?copper strip,stainless steel strip and manganese-white copper strip?.2.The effect of adding different concentration of gallium hydroxide to the electrolyte on the deposition/dissolution behavior of zinc negative electrode was determined by using nickel-plated steel strip as the negative substrate.It was found that the size of zinc deposited particles in basic solution was relatively large.The size of zinc deposited particles was refined to a certain extent after adding Ga?OH?₃ into electrolyte.With the increase of Ga?OH?₃content,the zinc deposited particles in surface coating were refined continuously.When the concentration of gallium hydroxide is0.1 mol/L,the particle size of zinc deposition is quite different from that of the base solution,which is related to the formation of gallium-zinc alloy by adding gallium hydroxide into the electrolyte.At the same time,adding gallium hydroxide can improve the self-discharge of zinc negative electrode to some extent.When adding 0.1mol/L gallium hydroxide,the coulomb efficiency of the battery increases from 59.9%to 69.1%when the battery is filled and stationary for 12 hours.3.By adding different concentrations of potassium stannate to the electrolyte and comparing with the basic solution of the basic solution,it is found that when the scanning speed is 1mV s^-1,the dissolution peak of the cyclic voltammetry curve decreases gradually with the increase of potassium stannate concentration and the width of the dissolution peak narrows gradually,which is related to the co-deposition of zinc and tin on the collector surface.With the increase of the scanning speed,this rule becomes more obvious.When three electrodes are used for constant current charging and discharging,the voltage in the charging process can be stabilized and the Coulomb efficiency is higher than that in the basic solution;when potassium stannate is added,the self-discharging phenomenon of zinc negative electrode can be improved to a certain extent.Compared with the basic solution,the self-discharging inhibition effect is obvious when 0.1 mol/L potassium stannate is added.This paper provides a simple method to suppress the self-discharge of zinc-nickel single-flow batteries.