Research Effect Of La And Ce Element Proportion Adjustment And Process Change On Microstructure And Properties Of AB₅ Type Hydrogen Storage Alloys

With the increasing awareness of environmental protection,people pay more and more attention to the development and utilization of hydrogen energy.In the development and application of hydrogen energy,it is very important to research and develop hydrogen storage materials with excellent properties.In this paper,commercial AB₅hydrogen storage alloy is taken as the research object.Among the main components of AB5hydrogen storage alloy,Pr and Nd are expensive and rising in price.In order to improve the cost performance of hydrogen storage alloy products,two series of alloys(La_1-xCe_x)(Ni Co Mn Al)_5.5(x=0,0.25,0.50,0.75)and(La_1-xCe_x)(Ni Co Mn Al)_5.5(x=0,0.25,0.50,0.75)were prepared by induction smelting.By means of XRD and semi-battery test system,the crystal structure,activation performance,discharge capacity,cycle life and high rate discharge performance of the alloy were studied respectively.In this paper,the melting process and heat treatment process system are studied,and the products with high cost performance are finally formed.The research results show that after completely replacing Pr Nd with Ce,after adjusting the ratio of La and Ce,it is found that the comprehensive performance is more advantageous(La_0.75Ce_0.25)(Ni Co Mn Al)_5.5.For(La_0.75Ce_0.25)(Ni Co Mn Al)_5.5alloy as the research object,the influence of heat treatment process on the structure and performance of the alloy was studied.The results showed that the sample with heat treatment temperature of 1050?and holding time of 10h had the best comprehensive performance.The retention rate of the alloy reached 79.51%after 200 weeks of cycling.The comprehensive performance of La_0.75Ce_0.25(Ni Co Mn Al)_x(x=4.96,5.06,5.16,5.26)with different stoichiometric ratios was better.Therefore,the influence of heat treatment temperature and time of the alloy on the alloy performance was further explored.The results showed that the sample with heat treatment temperature of 1000?and time of 8h had the best performance,with capacity of 328.6m Ah/g,capacity retention rate of 200 weeks of cycle up to 82.15%,and HRD of 5C ratio up to 85.4%,both of which met the requirements of market customers.The influence of melting process on the alloy La_0.75Ce_0.25(Ni Co Mn Al)_5.16was studied.The results show that the heat treatment process is 950?for 6h samples,the maximum capacity of the ingot alloy is 326.5m Ah/g,the discharge capacity is 255.05 m Ah/g after200 weeks of cycle,the maximum capacity of the fast quenched alloy is 322.9 m Ah/g,the discharge capacity is 259.95 m Ah/g after 200 weeks of cycle.The high power discharge capacity of ingot alloy is better than that of fast quench alloy.Comprehensively considering the composition ratio,the ingot alloy has advantages in capacity and ratio,and its service life can meet the customer's demand.