Research

Ground-based facility: Fire Safety for Space Exploration

Evaluating the thermal stability and safety of battery technology

The safety and performance of battery technology for space exploration are highly relevant as they are used for several applications (mobility devices, energy storage, crewed-space vehicles, small gadgets, satellites, etc.). Primary (non-rechargeable) and secondary (rechargeable) battery technologies would operate under extreme operational conditions, such as vacuum, vibration during launch and orbit, a wide temperature range, ionising radiation, and so on. According to NASA, the technological specifications of energy storage technologies for future planetary science missions must have high specific energy (≥250 Wh/kg) and long lifespan (15 years, 50,000 cycles) for rechargeable batteries, and more than 500 Wh/kg for primary batteries. Lastly, both primary and secondary batteries must operate under extreme conditions (-40 °C to 460 °C). Lithium-ion batteries are widely used in spacecraft applications; however, LIB technology still requires substantial improvement, as significant challenges remain in component degradation, thermal stability, and safety. Hence, studying and testing the thermal stability and safety of LIB and other battery technologies is indeed of high importance for future space missions.

The fire laboratory at ZAG-FRISSBE offers the opportunity to conduct thermal stability and safety studies on battery cells of various technologies for spacecraft applications.

Equipment available:

ARC (Acceleratory Rate Calorimeter) for thermal degradation studies (determining the onset of thermal runaway), see Figure 1
FTIR (Fourier Transform Infrared Spectroscopy) for characterising and quantifying the off-gassing in the far-field.
GC-MS (Gas Chromatography – Mass spectrometry) for characterising off-gassing.
Oxygen calorimeter for quantifying exothermic reactions (fire).
Other ad-hoc probes and equipment, such as thermocouples, cameras, data loggers and others, see Figure 2.

Figure 1: The Acceleratory Rate Calorimeter (ARC) assembly (left), and the standard and EVx combustion chambers (right). The assembly comprises combustion chambers that enable testing of cell components, from small cells (coin) to large battery cells (up to 100Ah). Both chambers sit in the blast box (left), where the experiments take place. The electronic cabinet (left) has the PC workstation, the ESU/OSU (for control and data acquisition from the calorimeter and add-ons), the PSU/PSU+ (provides power to the ARC system), and the CPU (for specific heat capacity measurements).

Figure 2: Schematic of an experimental setup with the leading equipment utilised during the overcharging abuse test of the selected LIB cells in the battery pack. The first test was for the lower-left cell, the second for the upper-right cell, and the third for the middle cell.

Type of tests and activities we can offer:

Energy release and gas characterisation of various batteries, from cell-size to pack level, fires up to 10 MW.
Flame characterisation of various types of geometry cells up to 100 Ah, see Figure 3 and Figure 4.
Specific heat capacity tests, up to 350 °C, for small to large cells up to 100 Ah.
Thermal degradation studies: from cell components to full-cell size of various geometries (up to 100 Ah).:

Heat-seek-wait method, see Figure 5.
Heating conditions: Adiabatic, ramping, isothermal, isoperibolic and step-isothermal.
Sensitivity 0.005-0.02 °C/min

Temperature and voltage measurements during safety testing, see Figure 6.
Extinguishment tests.
Training of students, space engineers and astronauts.
Other types of tests will be added in the future (abuse testing and standard testing): Cupper-slug calorimetry, Fractional thermal runaway calorimeter, Sensible enthalpy rise calorimeter, Thermal conductivity, Nail penetration and crash test, and Overcharge test.

Figure 3: Fire experiments of battery packs in the ZAG fire laboratory in Logatec, Slovenia. The experiments show extensive jet flames, a clear hazard of LIB technology.

Figure 4: Flames appearing after thermal runaway during the test with a battery pack. The duration of the flaming was very short, corresponding to the combustion of the gas released during the forced thermal runaway. The flames were confined to the gas phase and did not ignite any materials in the battery pack or the test setup.

Figure 5: Heat-seek-wait (HSW) test conducted in the ARC on LIB coin cells. In the HSW test, the cell is heated up in steps in semi-adiabatic conditions. That is, for each heat-up step, the ARC waits an additional step until self-reactions occur in the LIB cell, thereby identifying the onset of thermal runaway and other characteristic properties (e.g., delay time).

The facility is open for research proposals:

For any interested parties using the facilities, administrative and logistical coordination is handled by ZAG, which provides the specifications for all equipment available to investigators interested in utilising the facility. The respective research teams implement and conduct the experiments. The ZAG Technicians, who have been trained on the various apparatus, will introduce them and support the implementation of the experimental campaign.

Any proposed research projects can be funded by ESA, taking into account the operating costs of the laboratory facility. The ESA Continuously Open Research Announcements (CORA) programme offers funding for researchers from ESA member states or through the OSIP Platform. Note that ESA can fund up to € 50,000 per proposal, which includes the utilisation costs of the testing equipment and laboratory (excluding consumables and travel expenses). Before submitting any application to ESA, please don't hesitate to contact us for further details and information on the scope of the desired experiment or other activities.

ESA CORA Programme:

References:

Rojas-Alva, U., Mancini, L., Pranjić, A.M., Marini, E., Bozzini, B.. On thermal safety characteristics of rechargeable alkaline batteries based on zinc and manganese dioxide. Process Safety and Environmental Protection. 2025 May 11:107175.
Song L, Zhou Z, Ju X, Wang B, Rojas-Alva U, Zhou X, Yang L. Experimental study on thermal runaway characteristics and fire hazards of lithium-ion batteries in semi-confined space of transportation. Journal of Energy Storage. 2025 Aug 30;128:117220.
Rojas Alva, W. U., Uršič, M., & Jomaas, G. (2023). Fire safety of li-ion battery packs for aviation. SFPE Europe, 2(30, [ 5]), 27–33.

Images and results about the the equipment and selected experiments.

Figure 6: Temperature and voltage results for a test with a battery pack where the goal was to determine the safety design of the battery enclosure.

Contact:

Dr Ulises Rojas-Alva

E-mail: ulises.rojas-alva@zag.si