Adaptive Pouch Cell Chamber

Thermal runaway analysis provides unique insights into TR by allowing researchers to tally the total thermal energy release, plus the energy fractions liberated by venting, and energy that conducts through a cell casing – such as that of a 4Ah Amprius cell, or a 10Ah SVolt cell – both for which the APCC was originally designed to accommodate. This unique data is important in understanding Li-ion battery thermal design and analysis which may ultimately lead to safer Li-ion batteries with increased resistance to TR. The APCC is designed to work in tandem with the FTRC when coupled together for TR testing: The battery test subject is first sandwiched between the two chamber halves, or diaphragms, and then secured with fasteners. The APCC – which in different embodiments may have varying outlet diameters depending on battery sizing – is then coupled to the FTRC bore assembly using unique adapters and the aforemen-tioned pin system. A threaded port is centered on both diaphragms to accommodate one of several TR trigger mechanisms, such as a 400-watt heating element or a nail penetrator with a 9mm insertion depth. With the main hardware assembled, the user can leverage the APCC’s configurability into deciding to either rely solely on external instrumen-tation within the bore and baffle assembly (external of the APCC), or to utilize the APCC’s already tapped sensor ports to install thermocouples in a variety of different geometric layouts to provide better resolution of thermal measurements. Wiring can be run through the “battery cell connector support” to its multi-pin circular connector. After initiating TR in the battery cell, the FTRC will absorb the ejecta and gases expelled by APCC for analysis. The Adaptive Pouch Cell Chamber is at TRL 6 (system/subsystem model or prototype demonstrated in a relevant environment), and it is now available for licensing. Please note that NASA does not manufacture products itself for commercial sale. Innovators at NASA Johnson Space Center have developed an adaptive pouch cell chamber, or “APCC” for short, whose chamber halves com-press and constrain a battery pouch cell or a prismatic cell while it is induced into thermal runaway (TR) for analysis. The device comprises an adaptive diaphragm to accommodate variations in the thickness of these types of battery cells without requiring significant changes in the hard-ware. While NASA’s previous cell chamber design was state-of-the-art, the APCC brings numerous enhancements to the prior NASA design. The prior design required two technicians and approximately one and a half hours for setup between consecutive tests. This down-time was partially caused by the needed separation of the cell chamber from the fractional thermal runaway calorimeter (FTRC) bore where the thermal energy from a TR event is measured when expelled by the APCC. Addi-tionally, various internals such as heating elements and thermal sensors required refurbishment between each test in which TR was achieved. The APCC incorporates a novel two-pin quick-disconnect whereby the cell chamber is easily separated from the FTRC. This quick release de-sign increases battery testing throughput while reducing complexity and number of parts. Furthermore, the APCC internal hardware was designed to be fully reusable, lending itself to more reliable and consistent energy yield calculations sought after by battery cell testing and manufacturing industries.