Manganese-free rare earth-transition metal AB¿5?-type hydrogen-absorbing alloys having favorable high rate discharge characteristics, suitable for use in rechargeable batteries for electrical vehicles or hybrid electrical vehicles, include compositions of the general formula: R(Co¿u?Al¿v?M¿w?Ni¿l-u-v-w?)¿z?, where R is at least one element selected from rare earth elements and yttrium (Y), M is at least one refractory metal selected from Groups IVB, VB, and VIB of the periodic table, the value of u is from 0 to about 0.25, v is from 0 to about 0.10, w is from 0 to about 0.05, and z, the ratio of R(Co¿u?Al¿v?M¿w?Ni¿l-u-v-w?)/R, is from about 4.70 to about 5.50. The unit cell volume is from about 87 to about 88.5 A?3¿ at 25 °C, the plateau pressure is from about 3 to about 10 apsi at 25 °C, and the composition is essentially free of manganese. The figure shows a schematic diagram of the measurement of a Pressure Composition Isotherm (PCT) in a Sievert-type-gas-solid reactor.

Ab¿5?-type rare earth transition intermetallic compounds for the negative electrodes of rechargeable batteries
Application Number
Publication Number
Application Date
January 27, 2000
Publication Date
August 3, 2000
Chen Qun
Landi James
Ma Bao Min
Perng Tsong P
Santoku Corporation
H01M 04/38
C22C 28/00
C01B 03/00
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