H.E.L Group

BTC-130 Bench-Top, Battery Safety Testing, Adiabatic Calorimeter

BTC-130 Bench-Top, Battery Safety Testing, Adiabatic Calorimeter

The BTC-130 (Battery Testing Calorimeter) is a bench-scale adiabatic calorimeter designed to enable the testing of thermal, electrical, and mechanical stress tests on smaller-sized battery cells. Evaluation of these tests facilitates the assessment of the safety performance of battery cells, the battery’s safe operating limits, and research and development into the mechanisms of thermal runaway.  The BTC-130 also supports the use of small-volume spherical test cells, enabling thermal stability screening of individual battery cell components under adiabatic conditions.

• Component hazard Screening
• Characterizing differences in cell performance
• Defining safe operating limits
• Exploring thermal runaways and thermal propagation

Applications

Safety Testing

Component hazard screening:

• Batteries are used in a wide variety of environmental conditions and undergo internal heating and cooling from both normal use and stress conditions. Therefore, it is vital to understand how individual cell components will behave under a range of temperatures early on in development. If a new cell component has a low temperature of self-heating, it could pose a thermal runaway risk. Similarly, if a rapid increase in pressure accompanies a thermal event, or if toxic gases are produced, this may indicate the use of the component should be reassessed. The BTC-130 facilitates the use of small volume test cells in addition to supporting the testing of small battery cells. This enables the thermal stability of individual cell components to be assessed under adiabatic conditions and informed decisions on how to proceed with cell development to be made.

Define safe operating limits:

• It is essential to identify the safe operating limits of battery cells, modules, and packs in order to avert the risk of thermal runaway, and the potentially catastrophic consequences to which it could lead. Therefore, batteries need to be subjected to mechanical, electrical, and thermal stresses in order to define their safe operating limits.
• Thermal stability data from thermal stress tests can help define the safe working temperature of the battery
• The evaluation of over-charging and discharging rates allows the maximum safe voltage and maximum safe current to be determined
• The consequences of mechanical stresses and external short circuits (ESC) can be evaluated

Exploring thermal runaways and thermal propagation

• In general, most extreme conditions can result in thermal stress on the battery cell, which can lead to a thermal runaway. Therefore, for the development of safe batteries, it is essential to understand the mechanism of the thermal runaway in a cell, and how it propagates within a module or pack so that appropriate mitigation strategies can be implemented.The data obtained from the stress tests performed in the BTC-130 and the BTC-500 can be used to model a cell’s predicted thermal behavior. Successive onset temperatures of decomposition of components within the cell can be detected, and the resultant heat released determined. This can help to facilitate a mechanistic understanding of the thermal runaway within the cell. Further insight can also be derived from the external analysis of the composition of any evolved gases collected.

Performance Testing

Characterize differences in cell performance

• The BTC-130 and BTC-500 can be used to characterize the cell performance under more extreme operating conditions. The absolute limit of safe, repeated use can be assessed with the automated cycling of the battery cell until the heat generated by its discharge causes the onset of self-heating. Similarly, puncture tests provide an indication of the structural stability of the cell.