Equivalent Circuit Model for High C-Rate Discharge with an External Short Circuit

To improve emergency responder safety while handling damaged battery packs after a fire, better external short-based discharge methods are needed to mitigate hazards from stranded energy, including battery fire reignitions. This work uses a linear scaling on the diffusion-related parameters of an equivalent circuit model to capture the electrical and thermal behavior of a cell during an external short for different initial state-of-charge (SOC). As metrics of discharge effectiveness and safety, the model predicts the final SOC within 3%SOC and peak temperature within 2°C in the fitted, fully charged case. The same parameter set was applied to all initial SOC cases and parameter sensitivity is discussed. A key advantage of the proposed approach is that the main parameterization can be performed under normal operating conditions reducing the amount of hazardous testing required. This can then be used to explore a controlled discharge by adjusting the external resistance to avoid venting.