MANUFACTURE OF BUTTON TYPE BATTERY

摘要

PURPOSE:To prevent burrs from being produced in the secondary forming by placing a positive electrode compound material primary formed in a cylindrical shape with its end surface chamfered in a positive electrode case of a bottomed cylindrical shape followed by secondary forming. CONSTITUTION:Powder for the positive electrode compound material is primary formed in a cylindrical form and its one end surface is chamfered to made the positive electrode compound material 1. The primary formed positive electrode compound material 1 is inserted into a bottomed cylindrical positive electrode case 2, and secondary formed with a pressing die 3. Here the dimension of the chamber of the positive electrode compound material 1 in the direction of the thickness is chosen to be equal to or greater than the reduction in the thickness caused by the secondary forming. In this way the material in the top end corner of the positive electrode compound material 1 is crushed at the time of the secondary forming and enters the gap between the positive electrode case 2 and pressing die 3 to prevent burrs from being produced. Furthermore, the chamfered portion of the material 1 serves as a pooling space of the material 1 when it escapes upward at the time of secondary forming so as to prevent the material 1 from further going up and entering the gap between the positive electrode case 1 and the pressing die 3 and prevent the burrs from being produced.