Rare earth hydrogen storage materials can absorb and release hydrogen at lower temperatures. They are a kind of functional material and energy material with great development potential, and are also a strategic material in the field of green energy in the 21st century.
After adding certain metals to rare earth metals to form alloys, hydrogen can be absorbed and released at a lower temperature. This is the rare earth hydrogen storage material. According to the structure, it can be divided into two categories: AB5 type (LaNi5) hydrogen storage alloy and non-AB5 type rare earth hydrogen storage alloy.
At present, the industrialized hydrogen storage material is still the AB5 series, which is mainly used as the negative electrode material of Ni/MH batteries. In 2006, the A2B7 hydrogen storage alloy was industrialized in Japan. Among a series of hydrogen storage materials that have been developed, rare earth hydrogen storage materials have the best performance and are also the most widely used.
Development history of rare earth hydrogen storage materials
In the 1960s, the Dutch Phillips laboratory Zijlstra et al. discovered that SmCo5 rare earth intermetallic compounds can absorb hydrogen atoms. Vucht research found that LaNi5 and other rare earth intermetallic compounds can absorb and release hydrogen at room temperature.
In the 1970s, the American COMSAT laboratory developed a Ni/MH battery with LaNi5 as the negative electrode material.
In the 1980s, the Dutch Phillips Laboratory Willems made a breakthrough in improving the charge-discharge cycle stability of LaNi5 series alloys, and Ni/MH batteries using hydrogen storage materials as anode materials gradually became practical.
In the 1990s, nickel-metal hydride batteries moved from laboratory research to commercialization and practical use. The anode materials used were mainly LaNi5 hydrogen storage alloys.
At the beginning of the 21st century, the development of LaNi5 series hydrogen storage alloys has approached the theoretical capacity, and people have begun to develop alloys with higher hydrogen absorption capacity, starting with the ultra-low self-discharge nickel-hydrogen battery with La-Mg-Ni superlattice hydrogen storage material as the negative electrode. Put on the market.
Global market structure of rare earth hydrogen storage materials
At present, 95% of the world's rare earth hydrogen storage materials are supplied by China and Japan, and the output of hydrogen storage alloys in China exceeds 70% of the world's total output. With the popularization and application of hydrogen energy vehicles, the market demand for rare earth hydrogen storage materials will also greatly increase.