Accurate Measurement of the Contact Resistance During Internal Short Circuit in Lithium-Ion Batteries

Accurate internal short circuit (ISC) resistance measurement is of vital importance to understanding and modeling the ISC process and consequent thermal runaway (TR) behaviors. The current measurement of ISC resistance usually cannot quantify the contact resistance of two directly-involved parties for the ISC, and the measured ISC resistance generally contains additional components (depending on the ISC modes). To this end, we propose a novel experimental methodology to accurately quantify the contact resistance during ISC. By a series of auxiliary experiments, we exclude the resistance contribution from non-direct-contact components (but are directly contacted with the direct-involving parties). Two representative scenarios of ISC, i.e., direct contact of electrodes and contact of conductive metallic plates with electrodes, are characterized by the proposed methodology. An additional ISC scenario is used to validate the effectiveness and accuracy of the proposed methodology. Results provide a powerful tool to characterize the contact resistance during ISC for future possible experiment design and theoretical modeling for the understanding of battery safety issues.