V、Fe对TiMn_2储氢合金性能的影响

Influence of V and Fe on the performance of TiMn2 hydrogen storage alloy

为改善TiMn_2储氢合金的吸放氢性能,采用Fe或Fe、V取代合金中的部分Mn元素进行合金化改性。XRD(X-raydiffraction)分析表明Fe和V的同时引入使合金的相组成由TiMn1～2转变为TiMn1～2和δMnV相共存。P-C-T(Pressure-composition-temperature)测试结果表明,部分Mn被取代后合金吸放氢的滞后效应减小,储氢量提高。根据不同温度下的P-C-T测试结果求出吸氢焓变和熵变值,TiFe0.1Mn1.9和TiFe0.1V0.2Mn1.7合金的吸氢焓变分别为-36.9kJ/molH2和-21.19kJ/molH2。

To improve hydrogen absorption-desorption performance of TiMn2 alloy, partially manganesein the alloy was substituted by iron or iron-vanadium. XRD (X-ray diffraction) shows that thesubstitution results in phase constitution transformation from single TiMn1～2 to two phases coexistenceof TiMn1～2 and δMnV. P-C-T (pressure-composition -temperature)curves indicated that thehysteresis factor of hydrogen absorption and desorption decreases and hydrogen storage capacityincreases after manganese substituted by vandium. The entropy and anthalpy of hydrogen absorption could be calculated from P-C-T curves at different temperatures. The enthalpy values of TiFe0.1Mn1.9 and TiFe0.1V0.2Mn1.7 are -36.9 kJ/molH2 and -21.19 kJ/molH2 respectively.