The nickel-metal hydride battery, one of the major secondary batteries currently in circulation, was completed in 1990. In the same year, our company began manufacturing and selling rare earth-nickel hydrogen-absorbing alloys, and in 1994 started producing unidirectionally solidified thin strips of hydrogen-absorbing alloys using the strip casting method. Since then, we have become a major manufacturer of hydrogen-absorbing alloys using the SC method.
In 1995, our company also developed R-Mg-Ni hydrogen-absorbing alloys with antiphase boundaries and announced them both domestically and internationally (see References 1) and 2) below). Furthermore, we have developed new manufacturing methods for R-Mg-Ni hydrogen-absorbing alloys as an alternative to the SC method, and hold patents for both the alloys and the manufacturing processes (hereinafter collectively referred to as "our R-Mg-Ni hydrogen-absorbing alloy patents"). The main patents are shown in the table below.
We provide this patent information for your reference. For any inquiries regarding our patents and licensing, please contact our Intellectual Property department.

As stated above, our company holds numerous patents related to R-Mg-Ni hydrogen-absorbing alloys both domestically and internationally. When purchasing R-Mg-Ni hydrogen-absorbing alloys, we recommend that you confirm with your supplier in advance that the alloys in question do not infringe upon our R-Mg-Ni hydrogen-absorbing alloy patents.

Please be aware that in regions where our R-Mg-Ni hydrogen-absorbing alloy patents are in effect, the manufacture, sale, and other activities related to R-Mg-Ni hydrogen-absorbing alloys may infringe upon our R-Mg-Ni hydrogen-absorbing alloy patents, regardless of the purpose.

This alloy is characterized by a crystal structure with antiphase boundaries. When this alloy is observed using a high-resolution transmission electron microscope, the image shown in Figure 1 is obtained. This is an image of a crystal with a LaNi5-type single-phase structure having specific antiphase boundaries, where the arrows indicate the antiphase boundaries. The white dots in this high-resolution image correspond to the centers of the LaNi5-type unit cells. When this high-resolution image is analyzed with the aid of computer simulation, it yields the crystal structure with antiphase boundaries shown in Figure 2. When elements with larger atomic radii than Ni, such as rare earth elements and Mg, substitute for Ni at specific Ni sites in the LaNi5-type unit cell, antiphase boundaries are formed and the regularity of the crystal structure changes. It can be seen from the figure that the LaNi3 phase and La2Ni7 phase appear depending on the amount of substituted elements.