Research and application of Ti-Mn-based hydrogen storage alloys

Ti–Mn-based hydrogen storage alloys are considered to be one of the most promising hydrogen storage alloys for proton exchange membrane fuel cell applications,because of their good hydrogen absorption and desorption kinetics,low price,good activation performance,possession of high electrochemical capacity,and good cycling performance.The structure,performance characteristics,crystal structure of hydrides,development and application status of Ti–Mn-based hydrogen storage alloys were reviewed,and the methods to improve Ti–Mn-based hydrogen storage alloys were discussed:optimization of the preparation process,element substitution,and surface treatment.(1)In the study of the alloy preparation process,it was found that the use of the annealing process can significantly improve the high rate discharge performance,and cycling stability performance,increasing the maximum discharge capacity of the alloy electrode.In addition,using vacuum plasma spraying to prepare the electrode has better cycling stability and kinetic performance.(2)In element substitution,the effects of using Zr elements to partially replace Ti and Mn with Cr,V,Mo,and Fe on the hydrogen storage properties of Ti–Mn-based alloys were investigated.(3)In the study of surface treatment,palladium was plated on the surface of TiMn_(1.5) alloy by chemical deposition,and the strong affinity of palladium for hydrogen accelerated the cleavage of hydrogen molecules,which significantly improved the hydrogen absorption kinetics of TiMn_(1.5) alloy.Meanwhile,a new binary alloy system was formed by adding TiMn_(2) to MgH_(2),and it was shown that the addition of TiMn_(2) significantly improved the hydrogen absorption/desorption kinetics of the MgH_(2) alloy.Finally,the prospect of the application of Ti–Mn-based hydrogen storage alloys is presented,and the insight of further development of the alloy is offered.