The influences of V content on hydrogen storage properties in low vanadium Ti-V-Cr alloy

The microstructure and hydrogen storage property changes with V contents from 5at% to 35at% in Ti-V-Cr alloys were investigated. According to the SEM and XRD results, the microstructure of Ti-V-Cr alloy with 5at% V content consists of Cr_1.97Ti_1.07 phase, Cr₂Ti phase and small amount of Ti phase; besides the phases which is the same as the 5at% one, Ti-V-Cr alloy with 10at% V content still contains an amount of V based solid solution; when V content is up to 35at%, the main phase existing in the Ti-V-Cr alloy is only V based solid solution. Accompanying with the changes of the phase constitution and microstructure, hydrogen storage properties of Ti-V-Cr alloy vary remarkably. With the increase of V content, the maximum hydrogen storage capacity of Ti-V-Cr alloy increases continuously, and the hydrogen desorption ability increases either, but the kinetic and activation properties become worse. Among all the alloys studied, (TiCr)₆₅V₃₅ shows the largest hydrogen storage capacity, and the highest hydrogen desorption ratio at room temperature; Under the condition in the present research, the maximum hydrogen storage capacity and the hydrogen desorption ratio of the (TiCr)₆₅V₃₅ alloy are 2.86% (mass fraction) and 61%, respectively.