Inject-vent port design for energy storage device

A fluid injection and venting assembly (5) for use with a containment vessel (10), the assembly (5) comprising:

• an injection-vent port (25) that forms an opening between an ambient side of the assembly (55) and the vessel side of the assembly (50);
• a sealing interface (20) connected to the injection-vent port (25);
• an elastomeric member (15) constructed to seat in the sealing interface (20) and create a seal between the ambient side of the assembly (55) and the vessel side of the assembly (50);
• wherein the elastomeric member (15) is constructed to deform and thereby open the seal when exposed to a predetermined pressure, predetermined temperature, or both;
• wherein the assembly is operable in:
• a mass transfer configuration in which the elastomeric member (15) is not seated in the sealing interface (20) and the injection-vent port (25) is open to allow mass transfer through the injection-vent port (25);
• a sealed configuration in which the elastomeric member (15) is seated in the sealing interface (20) and the injection-vent port (25) is sealed to prevent mass transfer through the injection-vent port (25);
• and
• a vented configuration in which the elastomeric member (15) is displaced from the sealing interface (20) and retained between the injection-vent port (25) and a diffuser lid (45) to allow venting of fluid from the vessel side of the assembly (50) to the ambient side of the assembly (55) while preventing the elastomeric member (15) from becoming a projectile.