【作者】 赵罡；

【导师】 刘守平；

【作者基本信息】 重庆大学 ， 冶金工程， 2005， 硕士

【摘要】 钒基固溶体贮氢合金以其高的贮氢容量,吸放氢速度快等优点成为贮氢合金研究中的一个热点。目前,钒基固溶体贮氢合金主要是以钒、钛及其它纯金属通过真空感应炉或真空电弧炉进行制备。但由于纯的金属钒、钛等价格昂贵,影响了钒基固溶体合金的开发和研究。论文对自蔓延燃烧合成法（SHS）制备钒基固溶体贮氢合金进行了研究。实验以相对廉价的V₂O₅、TiO₂等氧化物为原料,利用自蔓延燃烧合成法制备出钒基固溶体贮氢合金V₃TiNi₀.56Al₀.2和V₃TiNi₀.56Al₀.1Cr_x（x=0.1-0.3）,并分析测试了合金的组织结构、贮氢性能和电极性能。得出了如下的研究结果: （1）自蔓延燃烧合成法制备V₃TiNi₀.56Al₀.2、V₃TiNi₀.56Al₀.1Cr_x（x=0.1-0.3）合金时,绝热温度约为2584-2879K,故反应热能够维持燃烧过程的自蔓延。（2）V₃TiNi₀.56Al₀.2合金铸态组织由BCC 结构的V、Ti 基固溶体主相和以NiTi为基的第二相组成,第二相以三维网状结构存在于主相的晶界处,第二相中有时还存在大量的Ti₂Ni。燃烧合成法制备出的合金中含有一定量的Al₂O₃、铝酸钙（CaAl₂O₄、CaAl₄O₇）、V₂O₃ 非金属夹杂。通过退火处理可使合金的成分更为均匀,固溶处理可使合金内部产生更多的新物相。（3）自蔓延燃烧合成法制备的钒基固溶体贮氢合金具备平衡吸放氢的能力,25℃时的平衡分解压约为0.01 Mpa 左右,铸态组织下,V₃TiNi₀.56Al₀.2 合金D#和C#样品吸氢容量分别为1.526wt%和0.805wt%。（4）V₃TiNi₀.56Al₀.1Cr_x （x=0.1-0.3）合金的充放电容量约在150mAh/g-260mAh/g之间,但容量衰减较快,循环伏安特性测试时合金具有明显的氧化峰,但氧化峰峰电流随循环次数增加而降低。更多还原

【Abstract】 Vanadium-based solid solution alloys became study hotspot because of their high hydrogen storage capacity and diffusion rate. Nowadays,Vanadium-based solid solution alloys manufacture mainly adopt pure Vanadium、Titanium and other raw materials and use vacuum electric arc or vacuum response smelt way to produce ,but the price of pure Vanadium is very expensive, it prevent the exploitation and appliance of Vanadium-based solid solution alloys. The Self-propagating High-temperature Synthesis technology to produce vanadium-based solid solution hydrogen storage alloys was investigated. Taking V2O5、TiO2 、Cr2O3 as raw materials and Al as a reductive agent, V3TiNi0.56Al0.2 、V3TiNi0.56Al0.1Crx(x=0.1-0.3) can been produced by SHS technology. the microstructure、hydrogen capacity and electrode properties of Vanadium-based solid solution hydrogen storage alloys are analyzed, the study results as following: (1) The adiabatic combustion temperature Tad of V3TiNi0.56Al0.1Crx(x=0.1-0.3) and V3TiNi0.56Al0.2 is about 2584-2879K, which testify the process of the Self -propagating can sustain. (2) It has been found that V3TiNi0.56Al2.3 alloy produced by SHS consists of two phases, the mian phase is a (Ti,V) solid solution with body centered cubic (b.c.c) structure,the secondary phase is a TiNi-based phase with a b.c.c structure containing TiNi and Ti2Ni, the secondary phase is precipitated and formed a three-dimensional network along grain boundaries of (Ti,V) solid solution main phase. Some oxides such as Al2O3, CaAl2O4, CaAl4O7, V2O3 is also found in the alloy. The treatment of anneal make the chemical compositions of the alloy is more homogeneous. After water quench treatment, the amount of the secondary phase in the alloy increases. (3) the alloy produced by SHS has the reversible hydrogen storage property,at 25℃,the equilibrium pressure is 0.01MPa, hydrogen storage capacity of V3TiNi0.56Al0.2 alloys D# and C# by SHS is respectively 1.526wt%and 0.805wt%. (4) The discharge capacity for V3TiNi0.56Al0.1Cr0x (x=0.1-0.3) alloy is 150mAh/g to 260mAh/g. however, the attenuation of discharge capacity is rapidly. The cyclic voltammetry experiments indicate that the alloy has a distinct anodic peak, but the anodic current decreases with the increasing of cycles.更多还原