After Loss of active material, if the BMS uses the original current limit and the original "1C" value for charging and discharging, the current density on the remaining active material (anode, cathode, or both) is higher than in the limit in the pristine cell, which in turn accelerates ageing further.

Increasing battery's internal resistance means that vehicle should charge and discharge battery at a higher current to deliver the same power. Passing higher current through the battery means the current density on the active materials increases. This leads to faster degradation.

BMS should use the remaining capacity estimate to narrow down the battery's charge and discharge voltage limits.

These positive feedback loops might be responsible for the "knee" in typical battery degradation dynamics. Other explanations: Rise of cell internal resistance can explain the capacity fade "knee", Cell capacity fade accelerates when Lithium deposition becomes irreversible.

Positive feedback loops of degradation might trigger runaway difference between cells in a cellgroup: see Cell size tradeoff.

Part of Cell degradation.



Degradation diagnostics for lithium ion cells, Figure 5 and its discussion