Question 1

What are the stages of Lithium-ion Battery Failure?

Accepted Answer

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 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.

Question 2

What gases does Li-ion Tamer detect?

Accepted Answer

Li-ion Tamer is designed to respond to volatile organic compounds (VOCs) which 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 vapours. 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.

Question 3

Does Li-ion Tamer detect the initial cell venting of different Lithium-ion Chemistries?

Accepted Answer

Lithium-ion battery chemistry refers to anode and cathode chemistry, such as LFP (Lithium FerroPhosphate or lithium iron phosphate) or NMC (Nickel Manganese Cobalt). Yes, Li-ion Tamer can detect the initial cell venting (off-gassing) of different lithium-ion battery chemistries. It does this by detecting the presence of battery electrolyte solvent vapours which are common to all battery chemistries. It is agnostic towards the types of anode and cathode chemistries used.

Question 4

How do you stop thermal runaway?

Accepted Answer

Li-ion Tamer can detect off-gassing of different lithium-ion battery chemistries; it does this by detecting the presence of battery electrolyte solvent vapours which are common to all batteries. The off-gas event, or cell venting, is a distinct stage in the stages of a battery failure which occurs prior to the onset of thermal runaway for most forms of battery abuse. Off-gas events are the earliest indicator of thermal runaway and once detected provides sufficient time to initiate containment measures, such as automatically isolating the components of the ESS or otherwise placing it in a safe condition. This action provides a barrier to the onset of thermal runaway. Other mitigating actions can be explored based on system constraints, including increased cooling, local alarms, remote alarms and ventilation activation to remove flammable gas accumulation.

Question 5

How many minutes of early warning does Li-ion Tamer provide?

Accepted Answer

The Li-ion Tamer product typically provides between 2 and 30 minutes warning of a thermal runaway event. The severity of the abuse factor greatly affects the amount of time between the cell venting and thermal runaway. When using the UL 9540A recommended failure method (overheating), Li-ion Tamer consistently delivers early warning with many different types of cell manufacturers, chemistries, and form factors.

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