The behavior of Li-ion batteries throughout their lifetime is nonlinear, with a plethora of dynamic electrochemical and mechanical phenomena occurring within the cell at any point in time, whether operating or not.
Two cells of identical geometry, chemistry, and history might respond differently when exposed to identical mechanical, thermal, or electrical stimuli.
The authors also state that Li-ion cells are complex systems. I don't agree with this. While Li-ion cells have some properties in common with complex systems, such as hysteresis and non-linearity, cells don't behave in emergent ways which we cannot predict by analysing the cell's components. Or, at least, so we hope :)
However, I'm not sure we have enough information in battery packs of small cylindrical cells even to estimate the parameters of the cells. The authors write:
[Electric Vehicles] contain sufficient on-board instrumentation, telemetry, and computing power to share detailed pack diagnostics and prognostics.
I think this can only be true for batteries of large prismatic cells, where we possibly can monitor the voltage and the current on every cell separately.
The authors also write that physics-based models help to identify critical operation conditions:
Identifying the most critical condition [under which a mechanical failure or short circuit is most likely to happen] is of great real-world value for the automotive industry to reduce the size of the test matrix, standardize the test condition, and guide the passive safety design of electric vehicles.
I think we more or less know that are these critical conditions are already: extreme temperatures (high and low) and high currents. But I agree this is useful that BMS can compute more precise power limits with a good physics-based model.
See also: