Trigger cell for triggering thermal runaway in batteries

A method of forming and operating a thermal runaway trigger cell for a battery cell, the method comprising:

• wrapping a first layer of first dielectric material at least in part around a surface of the battery cell, the surface extending from a cathode to an anode of the battery cell;
• wrapping a wire at least in part around the first layer of first dielectric material, wherein the wire is arranged in a vertical spiral manner around the battery cell, the vertical spiral has a first end near the anode of the battery cell, and a second end near the cathode of the battery cell, the wire has a first end section and a second end section that are nearer to the anode of the battery cell and further from the cathode of the battery cell, and the second end section of the wire is arranged at least in part above the vertical spiral and is separated from the vertical spiral by a third layer of dielectric material;
• wrapping a second layer of second dielectric material at least in part around the wire;
• coupling the wire to a power source;
• and
• arranging a temperature sensor in contact with at least one of the first layer, the second layer, and the battery cell.

A system for testing a battery cell, comprising:

• a wire comprising one or more metals at least in part wrapped around a battery cell, wherein the wire is arranged in a vertical spiral manner around the battery cell, the vertical spiral has a first end near an anode of the battery cell and a second end near a cathode of the battery cell, the wire has a first end section and a second end section that are nearer to the anode of the battery cell and further from the cathode of the battery cell, and the second end section of the wire is arranged at least in part above the vertical spiral and is separated from the vertical spiral by a dielectric material adhesive tape;
• an electrical barrier layer between the wire and the battery cell;
• a thermal barrier layer on the wire;
• and
• a thermocouple to measure a rise in temperature of the battery cell.