| Aluminum air battery is an ideal chemical power supply for solving current energy problems and environmental problems due to its high theoretical energy density(8100Wh g-1),capacity density(2980 Ah kg-1),environmental protection,safety,and rich resources.At present,the aluminum-air battery is in the initial stage of industrialization.Solving the self-corrosion of aluminum and improving the electrochemical performance of the aluminum-air battery are the key to the development of aluminum-air batteries with high specific capacity and high specific power.To this end,this subject studied salt-alkali double electrolytes and salt-based alkaline electrolytes,thereby suppressing self-corrosion of aluminum.In addition,this topic optimizes the structure of the aluminum-air battery and studies its electrochemical performance so that it can adapt to the application of power batteries.First,the performance of a salt-alkali dual electrolyte aluminum-air battery with a NaCl solution as the anode electrode electrolyte and a NaOH solution as thecathode electrode electrolyte was studied.The effect of NaCl concentration on the battery was studied,and it was determined that the battery exhibited better electrochemical performance when the NaCl concentration reached 3 mol L-1 or more.By studying the influence of temperature on battery performance,it is determined that 60?is the ideal temperature for battery operation.Based on the influence of pole distance on battery performance,a dual-electrode aluminum air battery structure with micro pole distance was designed,and based on the need for convenient replacement of aluminum anodes,the battery cell structure was optimized.Through constant current discharge,the specific capacity of the salt-alkali double electrolyte aluminum-air battery can reach2661Ah kg-1,and the peak energy density can reach 1325 Wh kg-1.However,the battery polarization is large,and the peak power density can only reach 2.2 mW cm-2.Secondly,based on the structure of a salt-alkali dual electrolyte aluminum air battery,adding a small concentration of alkaline solution to the salt improves the activity of aluminum in the electrolyte,that is,using a salt-based alkaline electrolyte as the anode electrode electrolyte.After electrochemical tests,it was found that the electrochemical performance of the battery was significantly improved by adding 1 mol L-1 NaOH to the NaCl solution,with a peak power density of 35 mW cm-2 and a peak energy density of 1870 Wh kg-1.In addition,the battery can maintain a specific capacity of about 1875 Ah kg-1 when discharged at a current density of 20 mA cm-2.Through the circulation of the electrolyte,the alkali can not be quickly consumed in the electrolyte cavity,and the alkali can be added to the storage tank to maintain its concentration.Finally,the structure of the aluminum air power battery with 7 mol L-1 KOH as electrolyte was designed and optimized,and its electrochemical performance was studied.Reduce the battery impedance by reducing the pole distance to 2 mm;by adjusting the electrolyte flow rate,it is determined that the power battery exhibits good electrochemical performance at an electrolyte flow rate of 40-60 ml min-1.After determining the battery pole distance and the electrolyte flow rate,an electrochemical test was carried out.The peak power density of the aluminum aerodynamic battery circulating at 60?with an electrolyte flow rate of 40 ml min-1 was 180 mW cm-2.The specific capacity of the battery at 50 mA cm-2 is 2447 Ah kg-1,and the energy density is about 3426 Wh kg-1.By designing the structure of aluminum anodes and battery cells,the problems of precipitation and aluminum waste are avoided,and kilowatt-level battery modules are designed.In summary,the use of salt-alkali double electrolyte aluminum-air batteries can effectively suppress the self-corrosion problem of aluminum-air batteries.The use of salt-based electrolytes enables aluminum-air batteries to have a higher specific capacity,and it is very promising to apply aluminum-air batteries that use them as electrolytes in portable devices.The optimized design of alkaline aluminum air power battery can also meet the needs of industrialization due to its good performance. |
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