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NASA’s pneumatic nail penetration trigger system embodies a fast and consistent nail penetration and retraction tool that tests battery cells within various steel and mylar enclosures. It is operated remotely with electric power and shop air pressure inputs. The trigger system is controlled by a solenoid valve and drives a nail to a set distance at 100 m/s for a precise and repeatable penetration injury to a battery cell. Contributing to the trigger system’s precision and repeatability is the nail penetration adapter that aligns the battery cell test enclosure with the trigger system and guides the nail by its internal barrel. The tip of the adapter threads into a variety of NASA battery cell test enclosures and provides an internal seating stop to ensure a proper targeting depth. On the actuator side of the adapter, two quick-release pins connect the adapter to the actuator mount which is bolted to the actuator subassembly. Removal of these pins readily allow for separation of the nail penetration adapter from the actuator mount and subassembly. During a TR event, the adapter is also designed to prevent flames, sparks, and ejecta from traveling into the actuator subassembly. While the versatile nail penetration adapter was originally configured to interface with NASA’s Fractional Thermal Runaway Calorimeter (FTRC), a blast plate test platform (BPTP), or cell enclosure for passive propagation resistant (PPR) methods, the adapter could be modified for commercial use with other battery testing systems. Companies interested in this technology may include those seeking to improve the safety of Li-ion battery cells and packs along with vertically integrated companies performing in-house TR tests during development of electrified systems like electric vehicles (EVs), electric vertical takeoff and landing (eVTOLs) vehicles, and electronic spacecraft components.

This technology is based upon a 120-watt IR laser is coupled to a fiber optic cable that is routed from the output of the laser into a series of focusing optics which directs energy onto a battery cell mounted to a test stand. When activated, heat from the laser penetrates the metal housing, heating the internals of the cell. At a specific temperature, the separator in the first few layers of the cell melts allowing the anode and cathode to make contact and initiates an internal short circuit. The internal short circuit then propagates throughout the battery eventually causing thermal runaway. The lower the wavelength of the laser used to produce the thermal runaway, the more heat-energy will be absorbed into the cell producing a faster result. The fiber optic cable can be terminated into a series of optics to focus the laser at a specific target, or the fiber optic cable can be stripped bare and placed next to the target to heat an isolated location. This method can also be used on a wide variety of cells, including Li-ion pouch cells, Li-ion cylindrical cells and Li-ion Large format cells. The innovation Triggering Li-ion Cells with Laser Radiation is at TRL 6 (which means a system/subsystem prototype has been demonstrated in a relevant environment) and the related patent application is now available to license and develop into a commercial product. Please note that NASA does not manufacture products itself for commercial sale.