Automatic pressurizing thermal battery

A thermal battery, comprising:

• a casing enclosing a chamber;
• a cell stack comprising a plurality of cells disposed within a first portion of the chamber, the plurality of cells in contact with one another at a pre-ignition state of the thermal battery;
• a pressurizing element disposed in a second portion of the chamber;
• and
• an actuator comprising a phase change material disposed in the second portion of the chamber and configured to urge the pressurizing element against an end of the cell stack to translate the end and decrease a length of the stack of cells when heated above a phase change temperature of the phase change material,
• wherein the pressurizing element is positioned between the stack of cells and the actuator;
• wherein the actuator is configured to be activated by an increase in temperature within the thermal battery above the phase change temperature from heat conducted from the stack of cells through the pressurizing element.

A thermal battery, comprising:

• a casing;
• a stack of cells disposed within the casing, the stack of cells comprising a first end and a second end;
• an actuator comprising a phase change material disposed within the casing;
• and
• a pressurizing element disposed within the casing and positioned between the stack of cells and the actuator;
• wherein the actuator is configured to receive heat conducted from the stack of cells to increase a temperature of the actuator above a phase change temperature of the phase change material to urge the pressurizing element against the first end of the stack of cells to impart a force on the first end of the stack of cells toward the second end of the stack of cells to decrease a length of the stack of cells and repressurize the stack of cells.