| abstract |
(57) [Problem] To provide a lithium secondary battery comprising a non-aqueous electrolyte and a positive electrode and a negative electrode capable of absorbing and releasing lithium in a cylindrical battery can, By effectively dissipating the heat generated from the positive electrode and the negative electrode, the temperature rise of the battery is sufficiently suppressed, and the cycle characteristics are improved. SOLUTION: By projecting a plurality of fins 5 on the outer peripheral surface of a cylindrical battery can 1, the surface area is increased 1.8 to 10 times. Each fin 5 is joined to the surface of the cylindrical battery can 1 by laser welding. |