To embody a negative electrode for a secondary battery having a high capacity and long life by treating the alloy powder obtd. by rapidly cooling the molten metal of a hydrogen occlusion alloy by a soln. contg. a conjugate unsatd. compd. having a specific value or above of conjugate π bonds in one molecule and an average mol.wt.
The hydrogen occlusion alloy of an MmNi5 system is preferably used as the hydrogen occlusion alloy in terms of improving the cycle life of the battery particularly when the alloy is used for the battery. Mm is a mischmetal. The molten metal of this alloy is preferably rapidly cooled by a revolving roll method, etc., and is made into the powder. The powder is treated by the soln. contg. a high degree of the conjugate unsatd. compd. In such case, the treating liquid is formed of the acidic or alkaline soln. and the treatment temp. is preferably set at room temp. to 150°C. The conjugate unsatd. compd. is an arom. compd. or heterocyclic compd. contg. ≥5 pieces of the conjugate π bonds in the one molecule and the average mol.wt. thereof is ≥100.
MIYAMOTO HIROYUKI
NOKUKI GENJI
KITAMURA HAJIME
