Battery Safety Testing

Battery safety is a much-discussed topic, and its importance remains front and center as the energy storage industry continues to expand. Our flammability team actively supports customers with battery safety testing. Flammability testing has focused on flammability analysis of the gas that is released during battery thermal events. These data are used to ensure the enclosure ventilation system and explosion relief panels are adequate for the installation.

Battery storage pic

Historically, Fauske and our customers have found adiabatic calorimetry to be a useful method for evaluating thermal stability of battery materials. We continue to expand our capabilities for testing batteries and battery materials. Some of our testing options are shown below, but please contact us if you have interest in other types of custom testing.

Testing Services

We experimentally determine the LFL, Pmax, and Kg as required by industry accepted standards such as ANSI/CAN/UL 9540A Ed. 4, which references a number of other standards (e.g., ASHRAE, ASTM, EN, ISO, NFPA and Canadian standards).

Other related testing services include:

VSP2

The standard VSP2 system is supplemented with an additional power supply and electrical load device, which for convenience are controlled separately from the VSP2 software. Also, for added safety, the standard 4-liter containment vessel is replaced with a larger pressure vessel available in the FAI flammability lab. Results demonstrate the efficacy of the VSP2 for analyzing battery explosions, and the method is scalable to larger batteries.

The VSP2 control software is configured to heat the lithium-ion cell at a constant rate from ambient to 350°C. The temperature, pressure, and lithium-ion cell voltage are measured and recorded. Additionally, the auxiliary and guard heater control power are recorded. The lithium-ion cell voltage is measured using customized software and pre-conditioning equipment while the VSP2 was used to record the temperatures and pressure and control the heaters.

Battery Cell Testing

  • Thermal Runaway
    • Testing is conducted on a preconditioned battery cell wrapped in a custom heater assembly with an optional guard for adiabatic tracking. The system is installed in a pressure containment vessel that allows us to control the atmosphere (air, nitrogen, humidity), and the cell is heated at a predetermined heating mode, undercharging or overcharging up or other electrical or mechanical abuse triggering systems. Cell voltage, gas temperature, center and cathode temperature and pressure signals are monitored throughout the runaway event. Key parameters include onset of cell venting, temperature and pressure rates relationships vs. time/temperature for kinetic extraction, and moles of non-condensable gas generated during runaway. Post test visual observations are taken, such as failure mechanisms.
  • Off-Gas Collection and Analysis
    • Following a thermal runaway typically done under inert conditions, a sample of the headspace gas at discrete times (cell vent, thermal runaway, post combustion) can be taken and analyzed for composition, and then be blended for further flammability testing.

Off-Gas Flammability Testing

  • Flammability Limits
  • LFL or UFL only (Pmax and Kg)
    • Knowledge of the LFL can be used to determine ventilation rates to prevent accumulation of flammable gas buildup (<0.25%)
  • Explosion Severity Test
    • Vent sizing for room or others.

Solvent and Electrolyte Solutions Testing

  • DSC (Differential Scanning Calorimeter) Test
  • TGA (Thermogravimetric Analyzer) Test
  • ARC (Accelerating Rate Calorimeter) Test
    • ARC test is completed using an accelerated rate calorimeter (ARC) where exothermic temperature rise rates and pressure generation rates are tracked adiabatically in a primarily closed system test setup. ARC data is typically used to assess thermal stability of cell components by identifying safety parameters, such as adiabatic time to maximum rate and extracting thermokinetic properties.
  • TAM (Thermal Activity Monitor) Test
  • ARSST
  • Flash Point Test
    • Typically closed atmosphere
  • Fire Point Test
    • Typically in open atmosphere. Need to sustain combustion.
  • Sustained Burning Test
    • When a material is classified as flammable because of flash point/fire point. This can be used to make the classification less severe.
  • Autoignition Temperature
  • Vapor Pressure
    • Eliminate boiling point.
  • Heat Capacity
    • The specific heat of a substance is the amount of energy required to raise the temperature of 1 gram substance by 1˚C. We can measure the heat capacity of solids at various temperatures with a variety of calorimetric tools. The heat capacity of a material or mixture can be used to assess general properties, such as insulating capabilities, is commonly used to size heating and cooling process equipment, and can help to improve the accuracy of a variety of simulations.
  • Oxidizing Liquids
  • Heat of Combustion
    • Used for classification of aerosol products and sizing dust collection systems.
  • Flammability Limits
  • Limiting Oxygen Concentration
  • Explosion Severity
  • Minimum Ignition Energy (MIE)

Membrane/Separator Materials Testing

  • DSC/TGA Tests
  • ARC Test
  • TAM Test
  • Heat Capacity
    • The specific heat of a substance is the amount of energy required to raise the temperature of 1 gram substance by 1˚C. We can measure the heat capacity of solids at various temperatures with a variety of calorimetric tools. The heat capacity of a material or mixture can be used to assess general properties, such as insulating capabilities, is commonly used to size heating and cooling process equipment, and can help to improve the accuracy of a variety of simulations.
  • Thermal Conductivity
  • Heat of Combustion
  • Oxidizing Solids
  • Ignition Temperatures of Plastics
    • Similar to AIT. Primarily for solids.

Electrolyte, Solids, Anode and Cathode Material Testing

  • DSC/TGA Tests
  • ARC Test
  • TAM Test
  • Heat Capacity
    • The specific heat of a substance is the amount of energy required to raise the temperature of 1 gram substance by 1˚C. We can measure the heat capacity of solids at various temperatures with a variety of calorimetric tools. The heat capacity of a material or mixture can be used to assess general properties, such as insulating capabilities, is commonly used to size heating and cooling process equipment, and can help to improve the accuracy of a variety of simulations.
  • Minimum Explosible Concentration (MEC)
  • Minimum Ignition Energy (MIE)
  • Layer Ignition Temperature (LIT)
  • Explosion Severity Test (Pmax and Kg)

Read a case study on how Fauske & Associates has used the VSP2 to test lithium-ion batteries