PolyJoule’s 3rd-gen conductive polymer battery self-extinguishes at 3,600 °F and delivers 10,000+ cycles

PolyJoule has unveiled its third-generation conductive polymer battery, featuring a new large-format prismatic cell design that incorporates a proprietary polymer cathode and a liquid salt electrolyte. This innovation targets sectors where the fire risks associated with lithium-ion batteries pose significant challenges, such as dense commercial buildings, residential settings, and indoor industrial environments. Unlike traditional batteries that rely on metallic crystalline lattices to store charge, PolyJoule’s technology utilises conductive polymers, which store charge along an organic molecular backbone. This approach eliminates the reactive metals and volatile electrolytes that commonly cause thermal runaway and fires in conventional battery chemistries. The safety credentials of PolyJoule’s battery were demonstrated in a rigorous test where a propane blowtorch heated the cell’s internal components to around 3,600 °F (1,982 °C). Despite the extreme heat and gas generation during the test, the battery self-extinguished immediately once the flame was removed, showcasing its resistance to thermal runaway. The company claims to be the first to validate through UL 9540A testing that its cells do not reach thermal runaway, a significant milestone in battery safety. Additionally, the new chemistry delivers a tenfold increase in energy density compared to PolyJoule’s first-generation cells while maintaining an impressive cycle life exceeding 10,000 cycles, all without requiring active thermal management. PolyJoule’s co-founder and CEO, Eli Paster, emphasised the fundamental safety principle behind the technology, stating that batteries should neither ignite nor propagate fires. MIT chemistry professor and co-founder Timothy Swager highlighted the electrolyte’s exceptionally low vapour pressure—one billion times lower than that found in lithium-ion batteries—underscoring the chemistry’s suitability for use in homes and businesses. This low vapour pressure reduces the risk of flammable vapour release, further enhancing the battery’s safety profile. Looking ahead, PolyJoule plans to open applications later this year for qualified solar, battery, and generator installers in selected markets, focusing on commercial, industrial, and residential energy storage solutions. The company’s breakthrough in combining high energy density, long cycle life, and intrinsic fire safety could mark a significant advancement in battery technology, particularly for sectors where safety concerns have limited the adoption of traditional lithium-ion systems. This development may pave the way for safer, more reliable energy storage options in environments where fire risk is a critical consideration.