A Battery Crush & Nail Penetration Tester is a high-security mechanical abuse platform used to evaluate the structural integrity and thermal stability of battery cells, modules, and packs. It simulates two of the most dangerous scenarios a battery can face: a vehicle collision (Crush) and an internal short circuit caused by a sharp object or dendrite growth (Nail Penetration).

The crush test evaluates the battery's ability to withstand external physical deformation without entering a hazardous state. Crush Geometry: Round/Hemi-spherical indenter that creates localized stress concentrations. Flat Plate that simulates a broader crushing force across the entire face of the battery. The test usually stops when one of three conditions is met: (a) A specific force is reached (e.g., 13 kN). (b) A sudden drop (e.g., >100 mV) indicates an internal short has occurred. (c) he battery is compressed to a certain percentage (e.g., 50%) of its original thickness.

The nail penetration test is designed to trigger a catastrophic internal short circuit by piercing the separator, allowing the positive and negative electrodes to come into direct contact. A high-strength, heat-resistant steel nail (typically Φ3 mm to Φ 8mm) is driven through the cell at a controlled speed (ranging from 0.1 mm/s} for slow-onset shorts to 80 mm/s for high-speed impact). Researchers monitor the cell for smoke, fire, or explosion. This test is crucial for verifying if "non-flammable" electrolytes or flame-retardant additives in new sodium-ion chemistries can prevent a "blowtorch" effect during a breach.

References:

B. Kotak, et al., Battery Crush Test Procedures in Standards and Regulation: Need for Augmentation and Harmonisation, Batteries 2021, 7(3), 63

B. Mao, et al., Failure mechanism of the lithium ion battery during nail penetration, International Journal of Heat and Mass Transfer, 2018, 122, 1103-1115

T. Ma, et al., Mechanics-morphologic coupling studies of commercialized lithium-ion batteries under nail penetration test, Journal of Power Sources, 2019, 437, 226928.