PolyJoule, a Massachusetts Institute of Technology (MIT) spin-off, has officially unveiled its third-generation battery chemistry technology—a conductive polymer battery capable of "self-extinguishing." In a demonstration video, engineers directly torched the battery's internal components with a propane torch at 3,600°F (approximately 1,982°C). Once the heat source was removed, the flames immediately self-extinguished, with no explosion or sustained combustion occurring.
"Batteries shouldn't start fires. Batteries shouldn't propagate fires. Batteries shouldn't catch fire," stated Eli Paster, Co-founder and CEO of PolyJoule. The company has chosen a technological path completely different from mainstream lithium-ion batteries—replacing the active metals found in conventional batteries with a conductive polymer cathode and a liquid salt electrolyte. This design fundamentally eliminates the thermal runaway risk that has long plagued the industry. Timothy Swager, MIT Chemistry Professor and PolyJoule Co-founder, explained: "Flammable materials typically contain active metals that react spontaneously with air and volatile liquids. The advantage of PolyJoule batteries is that they contain neither active metals nor volatile liquids."
The third-generation chemistry technology achieves a tenfold increase in energy density compared to the first generation, while also boasting a cycle life exceeding 10,000 cycles. Swager added: "PolyJoule has created a product that can be safely placed in homes and commercial locations. It uses non-flammable conductive polymers and liquid salt electrolytes, whose vapor pressure is a billion times lower than the electrolytes used in lithium-ion batteries."
The battery requires no thermal management system, simplifying system design and operational maintenance. The company also emphasizes its use of a domestic U.S. supply chain, reducing reliance on overseas critical materials. PolyJoule plans to begin accepting applications from solar and industrial installers later this year, targeting the commercial, industrial, and residential energy storage markets with this battery system.