Atomic spectral imaging of lithium-ion heterogeneity for proactive battery safety alert

Abstract

Ensuring the safety of lithium-ion batteries (LIBs) remains a critical challenge due to the risk of catastrophic failure known as thermal runaway (TR). Early warning of safety risks at the microstructural electrode scale remains a long-standing open problem. Here, real-time capable method for monitoring lithium-ion (Li-ion) distribution and thickness variations at electrode levels is shown to provide early warnings of battery failure. The work assesses the safety risk of lithium iron phosphate (LFP) batteries, known for their superior resistance to overheating, by utilizing the atomic spectral imaging, which provides a visual elemental fingerprint. When fully charged, a 47% graphite anode expansion is observed, which compromises structural stability and forms a Li depletion zone, acted as localized hot spots, accelerating the temperature rise and triggering thermal instability. Thus, the microscopic identification of internal details of electrodes enhances the LFP battery safety.