Lithium-ion battery thermal runaway mitigation: validated active discharge strategy

The problem

Lithium-ion batteries in electric vehicles and energy storage systems are susceptible to thermal runaway, where exothermic reactions can lead to fire, explosion, and cascading cell propagation. The competing effects of electrochemical heat generation and reduced state of charge during discharge create fundamental ambiguity, leaving a critical gap in validated mitigation strategies.

The solution

Researchers at the University of Tennessee Space Institute have experimentally demonstrated that active discharge is a reliable thermal runaway mitigation strategy for lithium-ion batteries, including situations in which thermal runaway has already begun. Using an Accelerating Rate Calorimeter under adiabatic and non-adiabatic heating conditions, the research identifies a validated discharge window within which state-of-charge reduction consistently dominates over electrochemical heat generation, preventing thermal runaway across a range of discharge currents, onset temperatures, and external heating rates.

Benefits

• Thermal runaway prevented across all tested discharge currents and onset temperatures
• Reduced SOC dominates over electrochemical heat generation even at aggressive discharge rates
• Discharge depth directly controls thermal runaway severity, enabling scalable mitigation
• Provides a validated parametric boundary under which for discharge-based thermal runaway is mitigated
• Applicable to electric vehicles and large-scale energy storage systems

Patent status

Patent Pending.