Research Of Modification And Hydrogen Storage Property On Li-N-H Complex And La-Based Alloys

The main contents of the thesis are: the influence of catalysts on the Li-N-H hydrogen storage materials was studied using x-ray diffraction and P-C-T test; the effects of partial substitution on alloys was investigated systematically by means of electrochemical test.1. Li-N-H complex hydrides were prepared by mechanical alloying. The hydrogen storage properties and the microstructures of the Li-N-H hydrogen storage materials with catalyst were studied. The P-C-T test results show that reversible hydrogen absorption/desorption temperature and plateau pressure decreased effectively with B added , plateau pressure increased with C added, the stability of hydrogen absorption/desorption and kinetic properties can be improved by adding B and C. The reversible hydrogen absorption/desorption capacity can also be improved with milled time.2. The microstructure and the electrochemical properties of La_1-xTi_xNi₄Co_0.7Al_0.3(x=0, 0.1, 0.2, 0.3) alloys were investigated systematically. La_1-xTi_xNi₄Co_0.7Al_0.3(x=0, 0.1, 0.2, 0.3) alloys were prepared in arc-melting furnace at argon atmosphere. XRD test results show that La_1-xTi_xNi-4Co_0.7Al_0.3(x=0, 0.1, 0.2, 0.3) alloys consist mainly of LaNi₅ phase. The results of electrochemical test analysis show that discharge capacity attenuation and the discharge capacity decreased, the cycle stability of La_1-xTi_xNi₄Co_0.7Al_0.3(x=0, 0.1, 0.2, 0.3) alloys electrode was improved, but its discharge plateau was declined as the increase of Ti. 3. The electrochemical properties of La_0.7-xCe_xMg_0.3Ni_2.5Co_0.5(x=0.1, 0.2, 0.3, 0.4) alloys were studied by mean of electrochemical test. A series of La_0.7-xCe_xMg_0.3Ni_2.5Co_0.5(x=0.1, 0.2, 0.3, 0.4) alloys were prepared by means of arc-melting and sintering: La_0.7-xCe_xNi_2.5Co_0.5(x=0.1, 0.2, 0.3, 0.4) alloys were prepared in arc-melting furnace and then sintered with Mg at argon atmosphere. Electrochemical analysis results show that the discharge capacity attenuation of the alloy electrodes increased firstly to 35.54% as x=0.2 and then decreased with the increase of x; the maximum discharge capacity of La_0.7-xCe_xMg_0.3Ni_2.5Co_0.5(x=0.1, 0.2, 0.3, 0.4) alloys is 155.45 mAh/g as x=0.