| The use of functionally graded materials(FGMs)as the sealing member of the liquid metal battery is conducive to solving the sealing problem of liquid metal batteries,enhancing the operating reliability of the liquid metal battery,reducing its operating cost,and conducive to the expansion of the industrial scale of the liquid metal battery.In this paper,the high-temperature molten salt corrosion behavior of FGMs by simulating liquid metal batteries operation has been studied with the aluminum nitride/molybdenum FGMs as the sealing member of the liquid metal battery,under conditions in which the lithium fluoride-lithium chloride-lithium bromide eutectic salt is used as the electrolyte,and the metal lithium as the battery negative electrode.Techniques,such as X-ray diffraction technology,scanning electron microscope and dispersion spectroscopy technology,Auger electron spectroscopy technology,and X-ray photoelectron spectroscopy analysis technology were taken for analysizing high temperature the corrosion behavior and related mechanism of aluminum nitride/molybdenum FGMs.The results show that the corrosion mainly occurs in the aluminum nitride area,and the corrosion products including nitrogen-lithium,aluminum-lithium mesophases or their compounds.The morphology of the corrosion products are affected by the distribution of aluminum nitride.With the gradient composition changes to the pure molybdenum region,the corrosion morphology gradually changes in the order of sphere,disk and octahedron.As the experimental temperature increases,especially at temperature higher than 600℃,the weakness of the bonding force at the phase interface will cause corrosion cracking on the sample surface.Therefore,it is recommended that aluminum nitride/molybdenum FGMs was used in liquid metal batteries.The temperature should be below 600℃. |
