| 摘要 |
PROBLEM TO BE SOLVED: To provide a sealed battery with a structure capable of preventing deformation of a side face of a battery case even if an inside pressure in the battery case increases, and surely cleaving a cleavage groove when the inside pressure in the battery case exceeds a threshold.SOLUTION: A sealed battery has a columnar battery case filled with an electrode body and electrolyte. The electrode body consists of a positive electrode, a negative electrode and a separator, and the separator has a porous membrane (I) mainly composed of a thermoplastic resin, and a porous layer (II) mainly composed of a filler with a heatproof temperature of 150°C or higher. A recess part recessed to inside of the battery case, is formed on a side face of the battery case when the battery case expands due to an increase in an inside pressure in the battery case. Front and rear long sides of a weld part between an outer can and a lid plate linearly extend, and weld weak parts having low weld strength are respectively formed on either edge side in right and left directions of front and rear long sides. |
