Patent attributes
Disclosed is a secondary battery obtained by rolling a cathode 31 and an anode 32 by interposing separators 33 and 34. The cathode 31 and the anode 32 have metal foils 31a and 32a, mixture layers 31b and 32b formed on the metal foils 31a and 32a, and foil exposure portion 31c and 32c that expose the metal foils 31a and 32a and are provided in one side in the width direction, respectively. The cathode 31 or the anode 32 has an insulation layer 35 that covers the mixture layers 31b and 32b, and a tip of a taper portion 32t of the mixture layer 32b, where the taper portion 32t is adjacent to the foil exposure portions 31c and 32c and has a thickness gradually reduced toward the foil exposure portions 31c and 32c, is exposed from the insulation layer 35.
