Design,Preparation And Electrochemical Properties Of Cathode Materials For Aluminum Air Batteries

Due to the high energy density and pollution-free performance,aluminum-air batteries have received widespread attention.The slow ORR reaction at the cathode of aluminum-air batteries hinders the practical application of aluminum-air batteries.Although platinum and its alloys have good catalytic performance,it is expensive and cannot be used in a large number of commercial applications,transition metal oxides are considered to be the most likely to replace platinum-based materials as cathode catalytic materials due to their low price and stable and excellent catalytic performance.This article focuses on the different types of spinel of nickel ferrite,nickel manganate,nickel cobaltate,and the materials composited with superconducting carbon black material and foamed nickel mesh as the research object,using scanning electron microscopy,linear polarization curve,cyclic voltammetry curve and other methods to analyze the microscopic morphology and electrochemical performance of the material,combined with first-principles calculations,theoretically analyze the reasons for the difference in electrochemical performance of different materials,the mainly results of the study are as follows:1.Under the four hydrothermal reaction temperatures,the microscopic surface morphology of nickel ferrite materials prepared at 130℃and 140℃hydrothermal reaction temperature is the best,and its electrochemical performance is not much different;The nickel manganate material prepared under 140℃hydrothermal reaction conditions has the best sample microscopic appearance,the largest polarization current density and reduction peak current density,and the smallest oxygen diffusion resistance;The electrochemical performance of the nickel cobaltate material prepared at the hydrothermal reaction temperature of 140°C is the best,and the microscopic morphology of the material gradually becomes better with the increase of the hydrothermal reaction temperature.Among the three spinel materials,the electrochemical performance of the nickel cobaltate material is the best,that is,the oxygen reduction performance is the best.2.The nickel ferrite/KB,nickel cobaltate/KB,nickel manganate/KB materials prepared at 130℃hydrothermal reaction temperature have higher polarization current density,oxygen reduction peak current density,and discharge voltage than a single spinel material,the electrochemical performance is further improved.Among the three materials,the electrochemical performance of the nickel cobaltate/KB composite is the best.The surface micromorphology of nickel ferrite/NF,nickel cobaltate/NF,nickel manganate/NF materials prepared at a hydrothermal reaction temperature of 130℃is more complicated.Compared with spinel/KB materials,various electrochemical performances are further improved.At the same time,the electrochemical performance of the nickel cobaltate/NF composite is the best,and the discharge voltage reaches0.995V when the discharge current density is 50m A/cm~2.3.Through the first-principles calculations of the supercells of the three materials,it is concluded that the electrons of nickel cobaltate in the three materials are easier to transfer,and the chemical reaction activity is the highest.At the same time,three materials’valence band and conduction band are composed of the outer orbital p and d orbitals.