Based on the fact that pure titanium and TiZr series have low equilibrium pressure of adsorbed hydrogen, strong ability to fix helium, and the formed hydride has stable chemical properties and high safety, it can be used for long-term storage of tritium gas, and the key problem to be solved is to reduce the retention; Based on the high desorption hydrogen balance pressure of TiFe system and TiMn system, it can be developed and studied for hydrogen storage and pumping in the production process. The key problem to be solved is to realize the repeated recycling of materials and reduce costs.
In order to solve the above problems, the current research direction is mainly element substitution. It is hoped that through the research of ternary or even multicomponent alloying, the hydrogen absorption and desorption and comprehensive properties of multicomponent alloys will be broken through.
1、 Pure Titanium
Compared with other materials, titanium has very superior performance in hydrogen storage. Firstly, titanium has the advantages of rapid adsorption and desorption of hydrogen. In addition, the equilibrium pressure of adsorbed hydrogen of titanium at room temperature (25 ℃) is 10-8 PA, and the loss of hydrogen is reduced due to the low adsorption equilibrium pressure; Secondly, in terms of safety, titanium hydrogen compounds are very stable. Even if exposed to air at room temperature, they are easy to handle. Unless the high temperature is applied, hydrogen will not be released; Finally, titanium is a low-cost metal. Titanium is rich in natural resources. Its content in the earth's crust is 5 times that of iron and 100 times that of copper.
The main disadvantage of titanium hydrogen storage is that the desorption temperature of titanium hydride is too high and the retention is large. In order to reach the equilibrium hydrogen pressure of 100KPA, it must be heated to a temperature near 800 ℃.
2、 TiFe system
TiFe series alloy is a kind of hydrogen storage material with good performance, and it is also a typical AB-type hydrogen storage alloy. In 1974, it was discovered by Reilly and Wiswell of the United States. As a hydrogen storage material, TiFe alloy has gradually been paid attention to by researchers and has done a lot of research.
After activation, TiFe series alloy has good hydrogen absorption and desorption performance, and its hydrogen absorption and desorption capacity are large, with the maximum hydrogen absorption capacity of (mass fraction), and its adsorption equilibrium hydrogen pressure at room temperature is 300kPa.TiFe alloys as hydrogen storage materials have many advantages, but there are also some problems: 1) activation is difficult; 2) The retention is large.
3、 TiZr series
Zr and Ti belong to group Ⅳ B metal elements. Similar to Ti, Zr is also a metal material with high hydrogen absorption density. Research shows that an appropriate ti/Zr ratio can improve the properties of the alloy; in addition, adding the third component metal M (where m is Co, Cr, V, Fe, etc.) can also improve the hydrogen storage performance of TiZr. Benvenuti C et al. Showed that TiZrV has good hydrogen absorption performance and has a wide application prospect in the fields of hydrogen and its isotope storage and purification.
