Pressure relief element, pressure relief device and battery

A method of manufacturing a pressure relief device of a battery module, the method comprising:

• injection molding a plastic pressure relief disk, an injection side of the injection molded plastic pressure relief disk having a contoured surface, and a second side of the plastic pressure relief disk, opposite the injection side, having a substantially flat surface, a thickness of the plastic pressure relief disk steadily decreasing from a raised central portion to a raised outer portion of the plastic pressure relief disk to define the contoured surface, the plastic pressure relief disk comprising a single notch that defines a predetermined breaking point between the raised central portion and the raised outer portion of the plastic pressure relief disk;
• mounting the plastic pressure relief disk into a base element of the pressure relief device;
• and
• mounting a protection cap on the base element of the pressure relief device.