| Boasting rather high energy density and environmental friendliness,aluminum fuel cells are the most likely to become the extended range power supply for next-generation electric vehicles.However,the current utilization of aluminum alloy anode materials is marked by a relatively high corrosion rate,which leads to low efficiency in energy storage and hinders the application of aluminum-air batteries to the market.Thus,in order to promote the development and application of aluminum-air battery technology,it is of great necessity to develop aluminum alloy anode materials with a low corrosion rate and good discharge performance and to carry out a deep and systematical probe into the corrosion mechanism of aluminum-air battery anode materials.This paper is based on Al-0.15In-0.025Sn-2.5Mg-0.005Pb-0.01 Ga and adopts multiple means of analysis and testing including the metallographic microscope,scanning electron microscope,testing for direct-assembly of batteries,EDS energy spectrum,theoretical simulation and electrochemical workstation.First of all,the paper studies the influence of aluminum of different purity on the discharge performance of the corresponding aluminum alloy anode materials and explores the best preparation process of related alloy anode materials;then it investigates the influence of Ga content in alloy on the discharge performance of electrode materials and the electrochemical properties of Al-0.15In-0.025Sn-2.5Mg-0.005Pb-0.035 Ga alloy in different KOH concentrations;lastly,it looks into the coulombic efficiency of Al-0.15In-0.025Sn-2.5Mg-0.005Pb-0.035 Ga alloy discharged in aluminum-air battery modules with different numbers of cells.Firstly,this paper analyzes the influence of aluminum of different purity on the discharge performance of aluminum alloy anode materials,finding that impurity elements like Fe,Si,Zn and Cu would bring about regional,uneven pit corrosion on the surface of aluminum anodes,and the finer the crystal grain size is,the more corrosion of aluminum anode materials there is.Through the process of combining hot rolling and cold rolling are obtained aluminum alloy anode materials in a uniform crystal grain size and with low corrosion performance and good discharge performance.Then,a discharge experiment under the condition of 6mol/L KOH electrolyte and constant temperature of 52? is carried out,with a finding that when Ga content in Al-0.15In-0.025Sn-2.5Mg-0.005Pb-x Ga alloy is 0.035%,discharge voltage of aluminum alloy anode materials gets into the most stable state,and coulombic efficiency hits the peak.A further study into the electrochemical performance of Al-0.15In-0.025Sn-2.5Mg-0.005Pb-0.035 Ga alloy in electrolytes with different KOH concentrations is conducted,which discovers that the optimal KOH concentration of the alloy is 4mol/L when it works.In the end,the discharge performance of Al-0.15In-0.025Sn-2.5Mg-0.005Pb-0.035 Ga alloy in aluminum-air battery module system with different numbers of cells is tested.It is found that the coulombic efficiency of aluminum alloy anode materials decreases along with the quadratic increase of the number of cells connected in series in a battery module.Furthermore,the results of the numerical simulation also suggest that the coulombic efficiency of aluminum alloy anode materials in a battery module drops as the working voltage of the battery module rises.The specific cause for the decrease of coulombic efficiency of aluminum alloy anode materials in a aluminum-air battery module is that electrolytic water hydrogen evolution corrosion occurs in the aluminum-air battery module designed at this stage,and that consumes the energy of aluminum anodes. |
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