The micro short-circuit is a failure mode where Li metal first precipitates on a negative electrode and then reaches a positive electrode; eventually a short-circuit occurs between the negative and positive electrodes and the battery voltage slightly decreases.
Puzzling micro-short circuit behaviors have been widely observed when utilizing Li metal anodes (LMAs) in all-solid-state batteries (ASSBs). Previous studies on Li/Li symmetrical cells have revealed a failure mechanism involving mechanical damage of solid-state electrolytes (SSEs).
However, soft-shorts are small, highly variable, and transient short-circuits that can lead to misguided data interpretation and precede permanent battery failure. This work presents numerous characterizations of soft-shorts in solid-state batteries along with modeling of soft-short dynamics.
Micro-short circuit (MSC) of a lithium-ion battery cell is a potential safety hazard for battery packs. How to identify the cell with MSC in the latent phase before a thermal runaway becomes a difficult problem to solve. We propose a diagnosis method to detect the MSC according to the remaining charging capacity (RCC) variations between cells.
A quantitative diagnosis method for the micro-short circuit fault of lithium-ion batteries is proposed. The remaining charging capacity is estimated using the charging cell voltage curve transformation. Estimated the leakage current and micro-short circuit resistance with low computational complexity.
Soft-shorts are diagnosable but also transient, and not every technique works for a given battery system. Soft-shorts could be anything from a forest of lithium growths accounting for >95% of the current flow to a thin dendrite in a crack or grain boundary that only decreases the cell impedance by 10%.