Fire-extinguishing current collector coated with melamine polyphosphate for lithium-ion batteries with high safety

Safety concerns, particularly related to fire and explosions, remain a critical limitation of lithium-ion batteries (LIBs). In this study, we propose an effective approach for enhancing the safety of LIBs while minimizing the degradation of their electrochemical performance by employing an aluminum (Al) current collector coated with a melamine polyphosphate (MPP) layer exhibiting fire-extinguishing properties. The MPP layer, composed of MPP, polyvinylidene fluoride (PVdF), and carbon black, generates phosphorous radicals (PO and HPO) derived from the thermal decomposition of MPP above 400 °C, which enables fire extinguishment by scavenging combustible OH and H radicals. The cathode prepared with an MPP layer exhibits improved self-extinguishing time and comparable electrochemical performance in LIBs compared to those of the cathode prepared with pristine Al in optimized conditions based on the physicochemical properties of the MPP safety layer.