Ultrasonic Characterization of Lithium Ion Thermal Runaway Conditions for Real-time Ultrasonic Enabled BMS Integration

Lithium-ion batteries have become a vital technology enabling renewable energy, electric transport and other low carbon technologies. However, there are significant concerns about their safety as there have been a small number of accidents in which batteries have caused fires and explosions, due in many cases by a thermal runaway phenomenon. Current techniques to identify potentially dangerous batteries are crude and provide very little time for reaction. This project seeks to develop means to detect degenerated conditions within batteries before they become dangerous using ultrasound methodology already developed to characterize the states of healthy batteries. Deviations from normal signals and the appearance of novel signal features associated with abnormal states will be identified and categorized as signatures of battery degradation phenomena.These will form the basis of an ultrasonic early warning system. Batteries and degradation mechanisms considered the greatest safety risk will be identified and selected for testing. A set of batteries prepared by hard cycling techniques with various types and degrees of degradation will be scanned with Titan’s ionView ultrasonic methodology. Features that appear in the ultrasonic signals caused by the degradation phenomena will be isolated and characterized as signatures of these mechanisms. This project will lead to the development of commercial systems to monitor batteries in energy storage applications to provide early warning of the development of degraded conditions within a battery that could lead to dangerous events. These could take the form of permanently installed hardware in battery stacks, either as standalone system or as part of a BMS, or a handheld device for use in routine maintenance. This will greatly reduce the probability of fires or explosions and encourage acceptance of lithium ion batteries for backup storage where energy generation is intermittent, e.g., wind turbines and solar arrays. The overall public benefits will be the expansion of renewable energy generation and the reduction of greenhouse gasses responsible for global warming.