CYLINDRICAL SECONDARY BATTERY

摘要

This cylindrical secondary battery includes: an electrode group formed by winding a positive electrode and a negative electrode with a separator therebetween; a current-collecting member formed by connecting a wound and layered conductive lead of at least one of the positive electrode and the negative electrode; and a battery container containing the electrode group and the current-collecting member and having an electrolytic solution injected thereto. The conductive lead is formed so as to be thinner toward a tip part from a root part; and when ?p is the tolerance of the pitch of the conductive lead and ?w is the difference of width dimension between the root part and the tip part of the conductive lead, the pitch of the conductive lead is set so as to make the variations of values obtained by dividing standard deviations of the number of layers of the conductive lead (which has been wound around the current-collecting member) by the average value of the standard deviations of the number of layers of the conductive lead, which is in the proper range as a predetermined value or less, and the width of said proper range is greater than the sum of ?p and ?w.