Prismatic battery

A prismatic battery comprising:

• a prismatic metal outer can having an inside surface comprising a first side surface, a second side surface, a third side surface, a fourth side surface, a bottom surface and a top surface, the first side surface being opposed to the third side surface, the second side surface being opposed to the fourth side surface;
• an insulating frame;
• an electrode group contained in the prismatic metal outer can,
• wherein the insulating frame is made of a resin sheet, wherein the resin sheet has a first elongated portion, a second elongated portion and a third elongated portion, the first elongated portion being connected with the second elongated portion at a first folding line, the second elongated portion being connected with the third elongated potion at a second folding line, wherein each of the first elongated portion, the second elongated portion and the third elongated portion has a third folding line to provide a first right peripheral portion a second right peripheral portion and a third right peripheral portion at a right side of the first elongated portion, the second elongated portion and the third elongated portion, respectively, and each of the first elongated portion, the second elongated portion and the third elongated portion has a fourth folding line to provide a first left peripheral portion, a second left peripheral portion and a third left peripheral portion at a left side of the first elongated portion, the second elongated portion and the third elongated portion, respectively, wherein the first right peripheral portion is separated from the second right peripheral portion by a first notch formed at the first folding line, wherein the second right peripheral portion is separated from the third right peripheral portion by a second notch formed at the second folding line, wherein the first left peripheral portion is separated from the second left peripheral portion by a third notch formed at the first folding line, wherein the second left peripheral portion is separated from the third left peripheral portion by a fourth notch formed at the second folding line, wherein the resin sheet is folded at the first folding line, the second folding line, the third folding line and the fourth folding line to form the insulating frame;
• wherein the first elongated portion is disposed between the first side surface and the electrode group, the second elongated portion is disposed between the bottom surface and the electrode group, the third elongated portion is disposed between the third side surface and the electrode group, that the right peripheral portion is disposed between the second side surface and the electrode group, and that the left peripheral portion is disposed between the fourth side surface and the electrode group.