Study On Electrolyte Circulation And Thermal Management System Of Aluminum Air Battery

As a kind of metal-air battery,aluminum-air battery has the advantages of high specific energy,good safety,green and environmental protection,etc.It also has the characteristics of "mechanical charging" by replacing the aluminum plate directly.At the same time,aluminum is abundant and cheep.So aluminum air battery has attracted great attention and has huge application prospects.However,the aluminum-air battery has some problems,the discharge product Al(OH)3 are accumulated in the battery and the large amount of heat are generated during discharging.The accumulation of discharge products will increase the internal resistance of the battery and reduce the electrolyte conductivity,resulting in a decline in the discharge performance,and it will also affect the life of the air electrode.In addition,if the heat can not be removed in time,a rapid increase in the temperature of the electrolyte will be caused,and aluminum corrosion will be accelerated.To separate the discharge products from the electrolyte of aluminum air batteries,an electrolyte circulation filtration system was designed based on backwash filtration.This system has a strong ability to separate the discharge products of aluminum air batteries.In a actual operation for 16 hours,the removal rate of Al(OH)3 reached 85.3%.At the same time,the filtration system has the advantages of simple structure and easy maintenance.Flocculant polyacrylamide(PAM)can accelerate the sedimentation of the discharge product Al(OH)3,and will not affect the discharge performance of the positive and negative electrodes of the aluminum-air battery.PAM is used in conjunction with the designed electrolyte circulation filtration system to separate the discharge products in time during the electrolyte circulation process,which can largely solve the problem of discharge product accumulation.To solve the temperature increase of aluminum-air batteries,we designed a heat dissipation system based on heat pipe and established a simulation model of the related heat dissipation system.The heat dissipation effect of the designed heat dissipation system was tested by electrolyte heat dissipation experiment and simulation analysis.The designed heat dissipation system has good heat dissipation effect and can effectively control the increase of electrolyte temperature.Besides,the effect of fan wind speed on the heat dissipation effect was studied.The simulation results show that the increase of wind speed is helpful to improve the heat dissipation efficiency,however,while the wind speed increases to a certain extent,the improvement of heat dissipation efficiency gradually decreases.