| 摘要 |
PURPOSE:To prevent the storage of undischarged negative electrode active material without reducing high-efficient discharge characteristics and elongate battery life by forming carboxymethyl cellulose having prescribed etherification and average polymerization degrees on the active material surface of a negative electrode board. CONSTITUTION:A nickel sintering base board 1 is dipped in solutions of cadmium nitrate and sodium hydroxide alternatively several times so as to fill a narrow hole 2 with cadmium hydroxide 3 of an active material. This base board 1 is completely charged/discharged in the sodium hydroxide by using a nickel board as the opposite electrode so as to make a caustic electrode. Secondarily, after a solution of 0.5wt% in density is prepared from carboxymethyl cellulose (CMC) of etherification degree of 0.7 or less and average polymerization degree of 1500 or more so as to coat on the caustic electrode, its surface is wiped with a dry cloth and exposed to 100 deg.C for one hour to be dried so that a film 4 of CMC is formed on the active material surface in the narrow hole 2. The film 4 is easily swelled in an electrolyte 5 so as to secure an effective response area. |
