Passive pressure relief device system based on thermobattery for a compressed gas storage tank

A method of heat activated pressure relief of a tank for storing a compressed gas, the method comprises:

• providing a battery comprising a continuous multilayer structure wrapped around said tank so as to conform to and cover a curved outer surface of said tank, said continuous multilayer structure comprising an anode layer in direct physical contact with said tank, a cathode layer disposed over said anode layer, and a thermally activated electrolyte layer separating said anode layer and said cathode layer;
• melting at least a portion of said thermally activated electrolyte layer by a spot heat source directed at any portion of said tank covered by said battery;
• activating said battery electrically by said melting of said portion of said thermally activated electrolyte;
• generating an electrical current by said electrical activation of said battery;
• opening a relief valve configured to be responsive to sufficient generation of said electrical current by said battery, wherein said relief valve is in communication with said tank;
• and
• releasing gas from said tank by the opening of said relief valve to relieve pressure within said tank.