Impurity distribution in distillate of terbium metal during vacuum distillation purification

The distribution rules of impurities in distilled terbium metal were investigated by vacuum distillation purificationexperiment and theoretical analysis.It is found that Ti impurity in distilled terbium is220mg/kg in the initial stage of the distillationpurification,increases slowly in the middle stage,and increases rapidly in the last stage,reaching2260mg/kg,and the modifiedseparation coefficient of Ti is1/19.02.The diffusion of the impurity Ti in liquid metal can reach a quasi-equilibrium state in theinitial stage of distillation purification and the calculated results agree well with experimental results;the distribution profile ofimpurity Cu is opposite to Ti,being380mg/kg in the initial stage,decreasing linearly to290mg/kg in the last stage,and themodified separation coefficient is17.99,and the theoretical calculated results are inconsistent with the experimental result.

Electrochemical characterization of MnO_2 as the cathode material for a high voltage hybrid capacitor

Manganese dioxide （MnO2） was prepared using the ultrasonic method. Its electrochemical performance was evaluated as the cathode material for a high voltage hybrid capacitor. And the specific capacitance of the MnO2 electrode reached 240 F·g^-1. The new hybrid capacitor was constructed, combining A1/Al2O3 as the anode and MnO2 as the cathode with electrolyte for the aluminum electrolytic capacitor to solve the problem of low working voltage of a supercapacitor unit. The results showed that the hybrid capacitor had a high energy density and the ability of quick charging and discharging according to the electrochemical performance test. The capacitance was 84.4 μF, and the volume and mass energy densities were greatly improved compared to those of the traditional aluminum electrolytic capacitor of 47 μF. The analysis of electrochemical impedance spectroscopy （EIS） showed that the hybrid capacitor had good impedance characteristics.

Formation mechanism and preparation of YAl_(2) intermetallics by electro-deoxidation with different sintering conditions

A study was carried out on the preparation of YAl_(2) intermetallics from mixed oxide precursors using the method of electro-deoxidation.Y2O_(3) and Al_(2)O_(3) mixed in molar proportions of 1:2 were sintered at temperatures ranging from 800 to 12000C for different hours.The sintered pellet was then electrolyzed in a molten CaCl_(2) at850℃using a graphite anode at a potential of 3.1 V.In this work,effects of sintering on the composition and the oxygen content in cathodic products were studied by X-ray diffraction(XRD)and oxygen-nitrogen analyzer.Sintering mainly affects the porosity of the pellets,and it is found that porosity decreases gradually with the increase in sintering temperature and the extension of sintering time.When sintered at 9000C for 4 h,the oxygen content in the cathodic product decreases to 1.85 wt%,and the efficiency of electro-deoxidation is 94.48%.At the same time,the mechanism of electrolysis was speculated.The results suggest that the formation of YAl_(2) is a multi-step process.During the reduction process from mixed oxides Y2O_(3)/Al_(2)O_(3) to YAl_(2) included many intermediate materials,such as YAlO_(3),Y3Al5O12 and YAl3,YAl_(2) intermediate alloy was prepared finally.

Electrochemical formation of La-Al intermetallic compounds in fluoride melts

The electrochemical formation of La-Al alloys in LiF-CaF_(2)molten salt on a molybdenum electrode at 1123 K was investigated by electrochemical techniques,such as cyclic voltammetry,square-wave voltammetry and open-circuit chronopotentiometry.The formation signals of four types of Al-La intermetallic compounds were observed.The Al-La alloy was obtained through galvanostatic electrolysis at 2.5 A·cm^(-2)for 3 h.The phase composition and microstructure of the electrolytic products were analysed by X-ray diffraction(XRD)and scanning electron microscopy with energy-dispersive spectroscopy(EDS).XRD results show that the phase compositions of the alloys are Al_(11)La_(3)and Al,and EDS results reveal 26.7 at%La in the alloy.