MOLDING METHOD OF ACTIVE MATERIAL FOR ELECTRIC CELL

摘要

PURPOSE:To unify the pressure distribution in a molded active material and prevent an occurrence of cracks or the like, by enclosing a positive-electrode pellet in a bottom portion of a cell casing and subjecting said pellet to a remolding under pressure by means of a metal mold having a pressing surface of specific configurations via a washer ring having an L-shaped cross-section. CONSTITUTION:A positive electrode pellet (a) which has previously been molded preliminarily is placed on the inner wall of a cell casing (1) and the molded again under pressure by a metal mold(b) via a washer ring(2a) of an L-shaped cross- section. Here, the pressing surface of said mold(b) is provided with a planer portion(c) having a diameter shorter by 0.04-0.10mm from the inner diameter phi1 of said washer ring(2a) and a height extending downwardly 0.02-0.5mm from the peripheral circumferential bottom surface of said metal mold(b). Thus, the pressure distribution is unified upon pressing said pellet and a positive electrode free of cracks or peeling can be formed.