Study On Electrolyte Additives For Aluminum Air Battery

Aluminum air battery is a kind of metal air battery with great potential.Its energy density is much higher than that of lithium ion battery,and it also has the advantage that other secondary batteries can’t be compared.When aluminum is consumed in the battery,it can be replaced by aluminum plate to achieve "mechanical "Charging",thus reducing the "charging" time,and the low price of aluminum,a wide range of sources,aluminum air battery has therefore attracted people’s attention.However,there are two main problems in aluminum air battery: the hydrogen evolution from the aluminum anode corrosion and the accumulation of Al(OH)3 colloid in the battery pack.In this dissertation,it was found that Na2 Sn O3,the traditional additive for aluminum air battery electrolytes,was found to reduce Sn O32-to Sn in the process of discharge to adsorb on the surface of aluminum electrode and hinder the formation of flow reaction.Therefore,two organic additives,glucose and Arabinose,were selected.By studying their effects on aluminum electrodes,air electrodes,battery performance and discharge products,it was found that the two additives can significantly reduce the self-corrosion of aluminum electrodes without affecting the electrochemical performance of aluminum air batteries.The corrosion inhibition efficiency reaches 90%.The above is an ideal aluminum air battery electrolyte additive.At the same time,the effect of composite additives composed of Na2 Sn O3 and cetyltrimethylammonium bromide(CTAB)was also studied.Through the analysis of air electrodes,aluminum electrodes,and discharge products,it was found that both were in suitable concentrations.The composition of the composite additive can effectively reduce the self-corrosion and improve the electrochemical performance of the battery,and it will not generate impurities during the reaction process.For the problem that aluminum air electrode discharge product accumulation,an organic flocculant sodium polyacrylate(PAAS)was studied in this paper.The addition of a small amount of additive can increase the viscosity of the electrolyte.The study found that PAAS can make The Al(OH)3 colloids condense into precipitates and thus flow out of the battery during the cycling of the electrolyte in the battery reaction.For this purpose,an electrolyte tank designed for use has been designed,to a certain extent,through a special high and low staggered baffle design.The circulation path of the electrolyte is constrained,so that the precipitation of Al(OH)3 is promptly deposited in the interior of the tank,and then discharged by a unified exhaust valve.During the experiment,it was found that the efficiency of the electrolyte tank collected by the structure was set to be 60%,which was three times compared with that of the ordinary box,and it had a good effect of depositing and separating the discharge products in the electrolyte of the aluminum air battery.