Preparation And Characterization Of XAgI·?1-x?Ag₃PS₄ Amorphous Silver Superionic Conductors

In recent years,the solid electrolyte received wide attention of domestic andforeign scholars.because of it'sstability?non-volatile?,safety?not explosive?,easy assembly and integration.Among them,the amorphous silver-ion solid electrolyte is an important kind of solid electrolyte materials,some of them have high ionic conductivity.so that this kind of superionic conductors have a broad application in the micro,solid-state batteries or electrochemical sensor and other fields in the future.we selected the composition of xAgI·?1-x?Ag₃PS₄ amorphous solid electrolyte system as the research object.Select the AgI and Ag₃PS₄ with the molar ratio of 1:1,then a series of samples,were prepared by mechanical milling method,With the rate of 800 rpm and different milling time.What's more,we also selected the AgI and Ag₃PS₄ with the molar ratio of 2:3?1:1?3:2 to prepare xAgI·?1-x?Ag₃PS₄superionic conductors.Via mechanical milling method With the rate of 800 rpm and 8h milling time.Those sampleswere examined by X-ray diffraction?XRD??differential scanning calorimetry?DSC?and nuclear magnetic resonance?NMR?et cl.The phase structure and heat-dynamic performance of samples had been investigated tofurther analyze structural origin.of variation in conductivity.The main results were as follows:?For the samples of 0.5AgI·0.5Ag₃PS₄:According to NMR,with the increase of milling time,the ionic conductivity at room temperature had the nonlinear change lawwhich increased at first and then decreased.At the milling time for 8 h,the ionic conductivity at room temperature of the sample achieved the maximum value of9.4×10^-4S/cm.Calculatedfrom variable temperature impedance,the activation energy achieved the minimum value.The study showed that the sample of 8h milling time had lowest value,and had a good advantage for conducting Ag⁺migration.According to XRD and NMR,the amorphization was well achieved when the sample was milled for 1h with the same milling rate.Proving that the mechanical milling method is a good method for preparing the amorphoussuperionic conductors directly.What's more,there is no?-AgI in a series of samples,proving that the conduct electricity of this conductor is not base on the structure of?-AgI,and a new amorphous ion conductive structuremay be generated.According to NMR analysis,a possible ionic conduction structure has been presented.?For the samples of xAgI·?1-x?Ag₃PS₄?x=0.4?0.5?0.6?:According to XRD,the result showed that the amorphization was well achieved for 8h milling time samples with different contents ofAgI.According to EIS,the ionic conductivity at room temperature of those materials increased gradually with more AgI.The largest value is 1.2×10^-3S/cm when the x is 0.6.What's more,the activation energy achieved the minimum value.This phenomenon may associate with the increase of conductive silver ions in samples.The above research results show that the mechanical milling method is an effective method for preparing xAgI·?1-x?Ag₃PS₄superionic conductors,and also prove the feasibility of using AgI and Ag₃PS₄ to prepare amorphous superionic conductors.This three kinds of molar ratio of samples which discussed in this paper are very useful reference for investigating other compositions in this system.