(中国科学院 上海微系统与信息技术研究所 能源科学与技术研究室, 上海 200050)
摘 要: 通过V4Fe对Mn的替代, 系统研究了储氢合金TiMn1.25-5yCr0.25(V4Fe)y(y=0, 0.02, 0.04, 0.06, 0.08)的储氢性能。 XRD结果显示: 合金为C14型Laves相结构, 合金的晶胞参数随着V↓4Fe量的增加而增大。 PCT结果表明: 适量的V4Fe替代Mn可增加合金的储氢量, 降低平衡压和减少滞后。 退火处理可使合金的相结构均匀化, 进一步改善合金的储氢性能。 TiMn0.95Cr0.25(V4Fe)0.06合金在1223K下退火处理6h后, 最大和有效储氢量分别为2.0%和1.75%(质量分数), 且滞后效应小, 适合于作为质子交换膜燃料电池的供氢源。
关键字: TiMn1.25-5yCr0.25(V4Fe)y; 储氢量; 平衡压; 滞后; 退火
(Laboratory of Energy Science and Technology, Shanghai Institute of Microsytem
and Information Technology, The Chinese Academy of Sciences,
Shanghai 200050, China)
Abstract:The reversible hydrogen absorption and desorption behavior of TiMn1.25-5yCr0.25(V4Fe)y(y=0, 0.02, 0.04, 0.06, 0.08) was investigated by substitution for partial Mn at 273K, 293K and 313K. XRD results show that the alloys have C14 Laves phase structure and with increasing content, the lattice paramters of alloy are increased. PCT results show that substitution can increase the hydrogen storage capacity, decrease the plateau pressure and the hysteresis of the PCT. However, it can also increase the slope of the PCT. After being annealed at 1223K for 6h, TiMn0.95Cr0.25(V4Fe)0.06 alloy has a low desorption plateau pressure (1.04×105 Pa at 273K and 2.72×105 Pa at 313K) and a small hysteresis (0.14 at 273K and 0.12 at 313K). The maximum and effective hydrogen storage capacities are 2.0% and 1.75%(mass fraction) respectively, which are suitable for hydrogen storage tanks in PEMFC.
Key words: hydrogen storage capacity; TiMn1.25-5yCr0.25(V4Fe)y; plateau pressure; hysteresis; annealing