| Fast ion conductor materials,also known as solid electrolyte materials,which have a low activation energy,high ionic conductivity and low electronic condutivity.It also has its advantage of safety,long service life,efficient etc during using.And it plays an important roles in the use of solid state batteries,electrochemical devices and the like.Meanwhile,it will be a significant part of the new generation electrochemical components.Campared with crystal materials,amorphous materials have its advantages of no grain boundary,high ionic conductivity,and the preparation is simple and easy to operate and so on.In this paper,the components of 0.8AgI·0.2Ag3PS4 were studied.The samples with high conductivity were prepared by high energy ball milling method and quenching-milling method.The characterization of XRD,DSC,Raman,TEM and AC impedance was carried out to explore the relationship between parameters and the sample with high conductivity.Meanwhile,the enthalpy relaxation caused by milling process and its mechanism was studied by milling As2S3.The primary contents and results are as follows:?1?High energy ball milling method and quenching-milling method at different milling time and speed was used to prepare 0.8AgI·0.2Ag3PS4 conductor samples.The XRD result indicate that both of the samples?milling time>5h,milling speed>600rpm?by the two method were amorphous samples.The ionic conductivity of the samples were measured by AC impedance method which showed the best ionic conductivity of the sample?milling 15h at 800rpm by milling method?at room temperature can be 3.6×10-3 S/cm.The ionic conductivity at room temperature of the samples increases with the milling time varies from 1h to 20h at a certain milling speed increased first and then decreased and it increases with the milling speed varies from 400rpm to 800rpm in a certain milling time.?2?Compared with theThe melt-quenching process could reduce milling time in a certain extent for that the milling raw was in a high state.The best ionic conductivity of the sample by melt-quenging-milling?milling 10h at 800rpm by milling method?at room temperature can be 2.1×10-3 S/cm.The mechanism of ionic conduction was studied by various analyses on the test of the samples.Based on the results of TEM show that that the amorphous samples contain a certain amount of AgI nanocrystals,which has a great surface area and is in a high state.It is benefit for the transfer for the ionics on the surface.Meanwhile,the amorphous structure also is good for the ionic transmission.Then,it indicated that the transmission of Ag+should be explain in both amorphous structures and AgI nanocrystals.?3?By setting a series of relaxation experiments with“annealing-calorimetry”method,the enthalpy relaxation behavior was detail studied.The milling samples are in a higher state than the bulk samples.Based on the simulation and analysis of KWW equation,the results imply that the samples of enthalpy relaxation time???decrease and the enthalpy relaxation mode changes with the measurement temperature increasing.With the measurement temperature rising,the relaxation mode changes from the stress dominating mode to structural dominating mode.The enthalpy relaxation behavior was observed at all of the As2S3 glass sample prepared by different milling time.It indicated that the heat releasing during upscan increases?20.16 J/g-20.69 J/g-21.31 J/g-22.76J/g?with milling time from1h to 6h and the enthalpy relaxation behavior of the As2S3 glass sample was caused by the Peer bond defects?As4S4 structural monomers and-S-S-bonds structural monomers?increasing during balls collision.Based on this,it is indicated that the enthalpy relaxation of As2S3 samples should be mainly attributed to the increase of disorder degree of sample structure after ball milling. |
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