Cr含量对TiMn1.2-xCrxV0.25Fe0.05合金吸/放氢性能的影响

对名义成分为TiMn1.2-xCrxV0．25Fe0．05(x=0．0，0．1，0．2，0．3，0．4)合金的储氢性能进行了研究．结果表明，合金的晶格常数和晶胞体积随Cr含量的增加而增大；随着Cr含量的增加，合金的吸／放氢平台压力和滞后效应减小．随着cr含量的变化，TiMn1.2-xCrxV0．25Fe0．05合金112峰半高宽(FWHM)和晶格常数c／a比率的变化与该合金吸／放氢平台斜率的变化一致，表明合金的平台斜率与合金的品格畸变关系密切．TiMn1.0Cr0.2V0.25Fe0.05合金具有较大的储氢量、低的平台压力、小的滞后和斜率，适于作为质子交换膜燃料电池供氢源的储氢瓶应用．

Effect of Cr Content on the Sorption Performance of TiMn1.2-xCrxV0.25Fe0.05 Alloys

The hydrogen absorption-desorption characteristics of TiMn_(1.2-x)Cr_xV_(0.25)Fe_(0.05)(x=0.0, 0.1, 0.2, 0.3, 0.4) alloys as a hydrogen storage tank were investigated. XRD results show that the lattice constants and the unit cell volume increase with increasing Cr content. The PCT results exhibit that the hydrogen sorption plateau pressure and hysteresis decrease with increasing Cr content. The change in the full width half maximum (FWHM) and c/a ratio with the change in the degree of slope present the same trend with Cr concentration, which implies that the slope behaviors in TiMn_(1.2-x)Cr_xV_(0.25)Fe_(0.05) system are closely correlated with the strain energy of interstitial site. In all cases, the TiMn_(1.0)Cr_(0.2)V_(0.25)Fe_(0.05) alloy exhibits a larger hydrogen capacity, lower plateau pressure, and smaller hysteresis and slope properties, which can satisfy the demand of hydrogen storage tanks for Proton exchance membrane fuel cell.