Simulation of single-layer internal short circuit in anode-free batteries

Abstract

The lithium metal battery technologies that can fulfil the high energy density goal have grave safety concerns and lead to fire/smoke, leading to battery failure. Out of all the causes of fire, internal short circuits (ISC) are the most common. The ISC safety test is considered a crucial checkpoint for battery design, but the present tests, like nail penetration and ball indentation, lack certainty and reproducibility in declaring battery safety. In light of these experimental limitations, we present an experimentally validated ISC simulation method that can elucidate fundamental mechanisms underlying ISC. The experimental/simulation method isolates the shorted single-layer from the unshorted layers, which helps in scrutinizing ISC and thermal runaway (TR) phenomenon. The present ISC model is flexible and computationally inexpensive compared to other 3D electrochemical thermal coupled (ECT) ISC simulations for a whole battery pack. We show the experimental validation of terminal voltage, short-circuit current, shorting resistance, internal temperature and other derived parameters of an ISC simulation of anode-free cell. Finally, the simulation model was used to do a parametric study for an anode-free battery (AFB) and the effect of cell design, and shorting parameters on ISC was scrutinized.