Nitrate residue removal from nickel electrodes - to prevent harmful nitrate-nitrite shuttle in nickel-cadmium alkaline accumulators

摘要

Nitrate residues are removed from the active mass of positive electrodes employed in alkaline accumulators. In preforming electrode, its polarity is reversed to a negative potential lying in the region of the nickel potential, so that the nitrate is reduced to ammonia gas which is evolved and leaves the system. The forming polarity is then applied in the correct direction until oxygen is evolved. The polarity reversal is pref. carried out in an electrolyte at 45-80 degrees C. Used esp. for the positive electrodes used in Ni/Cd accumulators, to avoid the nitrate-nitrite shuttle, which causes the discharge of the Cd electrode.