Study On Electrolyte And Circulation System Of Aluminum Air Battery

Aluminum air battery is a great potential for the metal air battery,its energy density is much higher than the existing lithium-ion battery,it also has other secondary battery can not match the advantages.When the aluminum anode in the aluminum battery exhausted,it can be replaced by aluminum plate to achieve "mechanical charge",the battery thus greatly reduces the “charge” time and metal aluminum has a low price,wide range of advantages,aluminum air battery therefore has attracted wide attention.However,one of the factors that constrains the long-term use of aluminum-air batteries is the problem of aluminum-ion battery discharge products.The discharge products and corrosion products of aluminum electrodes are both NaAlO₂.When NaAlO₂ reaches a certain concentration in the electrolyte,It will be converted into Al?OH?3,it is not easy to filter directly in the electrolyte,which brings a series of serious problems.First,a large number of NaAlO₂ will seriously affect the viscosity and conductivity of the electrolyte,the electrolyte conductivity decreases,increases electrolyte resistance of aluminum-air batteries,electrochemical performance of the battery drops;electrolytic solution becomes viscous,sticky severe form of shape,Greatly affect the service life of the electrolyte,and it is not conducive to the discharge process of gas emissions and the proliferation of reactants,aluminum air battery electrolyte cycle will bring a certain burden.In this paper,the effect of NaAlO₂ on the physical properties of the electrolyte was studied.The influence of NaAlO₂ concentration on the aluminum electrode and air electrode and its influence on the battery performance were studied.It was confirmed that the saturated NaAlO₂ in the electrolyte could make the aluminum The maximum power of the battery is reduced by about 15%;F-has a significant effect on the electrochemical behavior of aluminum electrodes.By using NaF as an additive to enhance the electrochemical performance of aluminum electrodes in electrolytes,the detrimental effect of NaAlO₂ on aluminum air batteries is reduced.In addition,the particle size of Al?OH?3 precipitated in the electrolyte by electrolytic aluminum was mainly distributed between 1 ?m and 20 ?m.And the use of water cyclone designed a set of aluminum air electrolysis system,it can collect aluminum air stack in the discharge process of Al?OH?3 particles,When the inlet flow rate of the hydrocyclone increases,the ability of the system to collect Al?OH?3 particles increases first and then decreases.When the inlet flow of the hydrocyclone is 0.67 L/min,the Al?OH?3 particles are collected the maximum energy can reach 84% in 30 min,the energy consumption of the whole circulatory system is about 6 W,and it has the advantages of simple structure and low energy consumption.PAM is a polymer with an elongated molecular chain.Its use in the electrolyte can increase the viscosity of the electrolyte without altering the conductivity of the electrolyte so that it does not change the internal resistance of the cell.And the electrochemical performance of aluminum electrode and air electrode are less affected.PAM flocculation in the electrolyte can accelerate the settling velocity of Al?OH?3 particles in the electrolyte,so that Al?OH?3 particles in a short time quickly settling to the bottom of the electrolyte barrel to achieve sedimentation separation;PAM in the electrolyte with thickening,increase the viscosity of the electrolyte but still has good mobility,this feature allows Al?OH?3 particles produced inside the aluminum air battery to adhere to the electrolyte,and then with the flow of electrolyte all out of the monomer cavity,so as to avoid Al?OH?3 particles in the battery stack,greatly extend the air electrode life.