Novel high-capacity hydrogen storage electrode material

Abstract

The invention relates to a novel high-capacity hydrogen storage material which is suitable for negative electrode material of Ni-MH secondary battery; the novel high-capacity hydrogen storage alloy is characterized in that: the material is La-Mg-Ni alloy, wherein the content of La is 30-38 percent (mass percent), the content of Mg is 0.6-2.6 percent (mass percent), and the remaining content is Ni, and the atomic ratio of the atomic ratio sum of the La and Mg and the Ni is controlled to be 1:3.5; in the novel high-capacity hydrogen storage alloy, by adding alloying elements Mg in the La2Ni7 type alloy, La atom is replaced by the Mg atom, so as to form stable substitutional type solid solution (La, Mg)2Ni7 alloy, and avoid decrystallizatoin tendency of the La2Ni7 type alloy in the hydrogen adsorption and desorption process. The material is used for manufacturing the negative electrode of Ni-MH secondary battery and greatly improve the discharging chemistry capacity and the electric circulating life of the hydrogen storage battery, thereby having commercial use purpose.

Description

【Technical field】 [0001] The invention relates to a novel high-capacity hydrogen storage electrode material, which belongs to the field of functional materials. 【Background technique】 [0002] In recent years, the demand for high-capacity secondary batteries has been increasing due to the spread of electronic products such as computers, communication equipment, home appliances, and audio-visual equipment. At the same time, due to the needs of environmental protection, all countries in the world are committed to the research and development of "green batteries" with high energy density, long life and no pollution. The traditional cadmium-nickel battery cannot meet the new requirements in terms of specific energy, and the cadmium used in the cadmium-nickel battery is toxic. In this context, metal hydride-nickel (Ni / MH) secondary batteries using hydrogen storage alloys as anode materials have attracted widespread attention and have achieved major breakthroughs in industrializa...

AI Technical Summary

Problems solved by technology

However, the hydrogen absorption and desorption pressure of the LaNi3 type alloy has a large hysteresis, and the hydrogen desorption curve has no obvious hydrogen desorption platform. Because the hydrogen desorption pressure of the alloy is very low, the discharge capacity of the alloy is only 150mAh / g, which is much smaller than its theory. capacity, not intended for use

At the same time, as a theoretical hydrogen storage material, the La2Ni7 alloy has a theoretical electrochemical capacity equivalent to that of the LaNi3 alloy, but it cannot be a stable electrode material because it becomes amorphous during the hydrogen absorption and desorption process.