GB190511353A - A Process for Regenerating Electric Accumulators. - Google Patents

Abstract

11,353. Luckow, C. May 30. Secondary batteries are regenerated as follows, when the capacity has diminished owing to the sulphation, contraction, disintegration, &c. of the active mass :-The normal electrolyte, sulphuric acid, is withdrawn, and the cells are cleansed by one or more rinsings with water. A dilute metallicsalt solution containing not more than 5 per cent of neutral or anhydrous salt is then run in. Preferably, 1-3 per cent solutions of salts of the light metals are used : for example, a solution of sodium, potassium, or magnesium sulphate, or of sodium or potassium borate, carbonate, or hydroxide, either alone or mixed with sodium or potassium sulphate, or of sodium or potassium borate or carbonate mixed with hydroxide. An electric current is then passed for some daya in the opposite direction to a charge, causing the desulphation of the active material, the reduction of the peroxide plates, and the oxidation of the lead plates. The current is then reversed, and after some days the plates come to their original state. After the salt solution has been run out and the cell rinsed with water and filled with sulphuric acid, the accumulator is ready for re-use. When the diminished capacity is merely due to sulphation, and not to contraction of the negative active material also, the regeneration is effected l:y an ordinary charging-current of several days duration. The sulphate is the most important ingredient of the regenerating-electrolyte, the other salts being converted into sulphate by the acid which remains in the cell in spite of rinsing, and by the acid formed during desulphation. A strong acid reaction must be avoided by renewing the salt solution, by diluting with water, by the addition of dilute solutions of potassium or sodium carbonate or hydroxide, or by the use of calcium, strontium, or barium carbonate, or hydroxide or other suitable means.