On The Impact of the Locality on Short-Circuit Characteristics: Experimental Analysis and Multiphysics Simulation of External and Local Short-Circuits Applied to Lithium-Ion Batteries

• Published in: Journal of the Electrochemical Society Vol. 167; no. 9; pp. 90521 - 90539
• Main Authors: Sturm, J., Rheinfeld, A., Buzon, D., Jossen, A.
• Format: Journal Article
• Language: English
• Published: IOP Publishing 20.04.2020
• Subjects: calorimetry; external short-circuit; internal short-circuit; lithium-ion battery; nail-penetration; rate capability
• ISSN: 0013-4651; 1945-7111
• DOI: 10.1149/1945-7111/ab8873

Emulating true, field-like internal short-circuits (ISCs) by experimental methods is a complex task with mostly unsatisfactory outcome. However, understanding the evolution and impact of ISCs is crucial to mitigate safety issues related to lithium-ion batteries. Local short-circuit (LSC) conditions are applied to single-layered, small-sized (i.e. <60 mAh), and single-side coated graphite/NMC-111 pouch-type cells in a quasi-isothermal test bench using the nail/needle penetration approach. The cell's impedance, capacity, and the contact resistance at the penetration site mainly define the short-circuit current and, hence, the terminal voltage and heat generation rate associated with polarization effects and electrochemical rate limitations, which are correlated to the cell's behavior during external short-circuits (ESCs) at various short-circuit resistances. Measuring the electrical potential between the needle and the cell's negative tab allows to evaluate the polarization across the electrodes and to estimate the short-circuit intensity. LSC simulation studies are used to correlate current flux and resistance to ESC conditions. Double-layered cells are penetrated to create short-circuit conditions within either a single or both electrode stacks to study the difference between multiple LSCs (e.g. during a nail penetration test) and a single LSC (e.g. due to a particle/dendrite). Post-mortem analysis reveals copper dissolution/deposition across both electrodes.