PolyJoule, an MIT spinout developing conductive polymer batteries, has unveiled a third-generation battery chemistry designed to self-extinguish under extreme thermal conditions for stationary energy storage applications.
The Boston-based company said the new large-format prismatic cell combines a proprietary conductive polymer cathode with a liquid salt electrolyte and is aimed at commercial, industrial and residential battery energy storage systems (BESS).
According to the company, the chemistry delivers a 10-fold increase in energy density compared with its first-generation technology while maintaining a cycle life of more than 10,000 cycles. The company also claims the batteries do not require active thermal management systems.
PolyJoule: first to prove conductive polymer cells don’t go into thermal runaway
“PolyJoule has always been at the forefront of energy storage safety,” said Eli Paster, PolyJoule’s co-founder and CEO. “We were the first company in the world to prove through UL 9540A testing that our conductive polymer cells do not go into thermal runaway. We approached this next-gen chemistry with a very simple thesis: Batteries shouldn’t start fires. Batteries shouldn’t spread fires. Batteries shouldn’t catch on fire.”
Unlike lithium-ion, lead-acid, sodium-ion and nickel-based batteries, which rely on metals as the active charge-storage component, PolyJoule’s technology stores charge along an organic conductive polymer backbone. The company said this eliminates dendrite formation and reduces the risk of thermal runaway.
To demonstrate the chemistry’s fire resistance, the company released footage of a full-size cell exposed to a propane blowtorch generating temperatures of almost 1,982°C (3,600°F). The company said the flames extinguished immediately after the external heat source was removed.
“Materials that have a propensity to catch fire often contain reactive metals that spontaneously react with air and volatile liquids,” said Timothy Swager, the John D. MacArthur Professor of Chemistry at Massachusetts Institute of Technologyand a PolyJoule co-founder. “The advantage of PolyJoule’s batteries is that they have neither. PolyJoule has created a product that can safely be put inside homes and businesses, using non-flammable conducting polymers and a liquid salt electrolyte that has a vapor pressure a billion times lower than that of the electrolytes used in Li-ion batteries.”
PolyJoule said the new chemistry forms part of its strategy to target markets where battery safety is a primary requirement, including installations in buildings and urban environments. The company plans to begin accepting applications later this year from selected solar, battery and generator installers.
