The Studies On Electrochemical Properties Of Zinc Oxide Synthesized By Complex Precipitation Method

In this paper,we mainly describe the synthetic method of the zinc anode active material of ZnO in secondary zinc nickel batteries. We expound the existing problems in secondary zinc nickel batteries, such as zinc electrode’s deformation, dendrite, corrosion and passivation, nickel cathode’s poison failure. We mainly study the synthesis method of zinc anode active material of ZnO, including various complexing agents’ ratio, additives’ effect on the tap density and electrochemical performance of ZnO.In this work, we use the complex precipitation method, using sodium citrate, ethanol amines and ammonia water mixture as bottom liquid complexing agents, then alkali source and a source of zinc solution are added in two-way, additives such as PEG-600, PEG-6000, twelve benzene sulfonate are beneficial for producing zinc oxide high tap density which have good electrochemical performance in some situations.The ZnO samples preparation for XRD testing of the chemical structure, morphology observation by SEM, through the charging and discharging device for charge and discharge test. For zinc nitrate, zinc sulfate, zinc acetate systems, when the molar ratio of Zn2+, sodium citrate is between11.88to16.05, complexing agent such as ethanolamine, diethanolamine, triethanolamine respectively added in ammonia and the total volume is15ml. when the mixed volume ratio is right,we can prepare ZnO with high tap density. When we add the appropriate amount of additives PEG-600, PEG-6000, twelve sodium dodecyl benzene sulfonate, we can get zinc oxide with high tap density and good electrochemical performance.l.In zinc nitrate system, ethanol amine and ammonia compounded series, we found only ethanol amine and sodium citrate as the bottom liquid complexing agents, ZnO’s tap density was about2.4g/cm3, and it’s0.3C and0.5C discharge capacity was550mAhg-1,400mAhg-1, then we added proper amount of PEG-600for modification, tap density decreased to2g/cm3, it’s0.3C discharge specific capacity is up to about550mAhg-1.We could get the zinc oxide with high tap density and better electrochemical performance, when we mixed diethanolamine, triethanolamine with ammonia respectively.2.In zinc sulfate system, ethanol amine and ammonia are compounded.we found only ethanol amine and sodium citrated as the bottom liquid complexing agents, ZnO’s tap density is very low,0.1C and0.3C discharge specific capacity is only about300mAhg-1, adding proper amount of PEG-6000, tap density increases to about2.5g/cm3,0.2C and0.3C discharge specific capacity is up to about600mAhg-1, ZnO’s performance is increased.The tap density of the zinc oxide was improved, when we mixed diethanolamine, triethanolamine with ammonia respectively, but the electrochemical performance was not good.We could synthetize zinc oxide whose tap density was high of about2.7of g/cm3, and it’s0.3C and1C discharge specific capacity was500mAhg-1, about300mAhg-1,with just the right amount of ammonia water mixed with sodium citrate as complexing agents, which were suitable for high rate discharge.With an amount of PEG-6000, sodium dodecyl benzene sulfonate modified,ZnO’s tap density decreased to around2.4g/cm3,0.3C and0.5C discharge specific capacity was about600mAhg-1,500mAhg-1.3.In zinc acetate system, triethanolamine and ammonia compounded series, we found only triethanolamine and sodium citrate as the bottom liquid complexing agents,ZnO’s tap density was about2.5g/cm3, and it’s0.3C and0.5C discharge specific capacity was up to450mAhg-1,530mAhg-1. We added SDBS as modification,then it’s tap density increased to about2.9g/cm3,0.3C and0.5C discharge specific capacity was up to550mAhg-1,500mAhg-1.The overall electrochemical properties have been improved.We could get the zinc oxide with normal tap density and general electrochemical performance, when we mixed ethanol amine, diethanolamine with ammonia respectively. In this paper, we did research on compounding zinc oxide with high tap density,we used ammonia water with sodium citrate and ethanol amine as the bottom liquid complexing agents in different zinc salt system. For different zinc sources, complexing agents and additive proportion, had been studied in this research.