Patent ID: 8758928

Claim:
A lithium secondary battery comprising: a conductive structure comprising; a core disposed in a case, two lead terminals fixed at both ends of the core, an electrode assembly winding about the core, each lead terminal including a disk-shaped flange and a cylindrical-shaped collecting area extending downward from the flange to connect to the core, the electrode assembly including a positive layer with an uncoated positive lead area, a surface coated with positive electrode material, a negative layer with an uncoated negative lead area, a surface coated with negative electrode material, and at least one separating layer for separating the positive layer from the negative layer; characterized in that: a clasping assembly configured to enable the electrode assembly to keep in electrical contact with the lead terminals includes at least one screw rod, two pressing pieces, and two fixing nuts for fixing these components and the case; wherein the pressing pieces of the clasping assembling are arc-shaped for mating with the cylindrical-shaped collecting area, an inner surface of the pressing pieces of the clasping assembly is a stepped structure having a high portion and a lower portion, so that after the lower portion is pressed against the uncoated positive and negative lead areas, the coated area of the electrode assembly will be flushed with the high portion, and wherein the screw rod is inserted through a through hole of one of the pressing pieces, a through hole in the cylindrical-shaped collecting area, a through hole of the second pressing piece, and then is fixed thereto by one of the fixing nuts, so as to clamp the positive lead area or the negative lead area tightly against the cylindrical-shaped collecting area, and thus the positive lead area or the negative lead area are maintained in a tight electrical contact with the cylindrical-shaped collecting area.