Early warning to help prevent Li-ion battery fires

Stage 1: Abuse 

Electrical (over-charge/discharge, or internal manufacturing defects). 

Thermal (external heating or operating the battery outside its specified temperature). 

Mechanical (physical damage to the cell).  

 Stage 2: Initial cell venting (off-gas event)

The battery electrolyte will convert to gas, increasing the internal pressure and venting to the outside through the pressure relief vent or rupture. This gas release is distinctly different than the release of gases at thermal runaway and often occurs several minutes prior to thermal runaway. 

Stage 3: Thermal Runaway 

With increasing internal battery pressure and temperature, the separator will melt down and rupture, releasing smoke and potentially igniting the electrolyte solvent. Thermal runaway enables propagation of abuse and failure to adjacent cells, with any resulting fire further increasing the risk. 

The Li-ion Tamer GEN 3 system is an advanced lithium-ion battery off-gas detection system that provides early detection of ongoing battery abuse across a wide range of battery storage environments (modular, containerized, large scale). 

Li-ion Tamer is designed to respond to volatile organic compounds (VOCs) that are emitted during a lithium-ion battery off-gas event that occurs prior to thermal runaway. The initial off-gas event consists of primarily battery electrolyte solvent vapors. 

The off-gas event may also be referred to as the initial cell venting and is defined as the event in which the cell case vents due to a rise in the internal pressure of the cell. 

Li-ion Tamer will also detect the composition of gases (CO, H2, hydrocarbons, etc.), released at thermal runaway.

The Li-ion Tamer Sensor MOS detects electrolyte vapor generated during initial off-gassing event, prior to thermal runaway.  The early detection of such events enables proper mitigation steps to be taken to avoid a catastrophic thermal runaway failure.  

In addition, it also detects hydrogen and carbon monoxide gases released during thermal runaway of lithium-ion batteries. The detection of these gases enables proper management of flammable gas accumulation to avoid explosive conditions.

No, despite the presence of BMSs, thermal runaway events can occur. BMSs monitor temperature and electrical loading but these systems may have insufficient resolution or granularity at a cell level, enabling an initial cell failure to occur. BMSs may also experience sensor failure. 

The Li-ion Tamer product provides an independent monitoring solution for lithium-ion batteries and is an essential safety layer within a Failure Modes Effects Analysis (FMEA) for improving the overall safety.

Li-ion Tamer Sensor MOS typically provides between 2- and 30-minutes warning of a thermal runaway event. The severity of the abuse factor greatly effects the amount of time between the cell venting and thermal runaway. 

When using the UL 9540A recommended failure method, Li-ion Tamer consistently delivers early warning with many different types of cell manufacturers, chemistries and form factors.