Meaning
Electrochemical signatures observed during the discharge of a battery cell indicate the dissolution of plated metallic lithium from the anode surface. A lithium stripping peak appears on a differential capacity or voltage curve when the metallic lithium plated during charge is dissolved back into the electrolyte. This peak provides a clear diagnostic indicator of prior lithium plating, allowing engineers to verify the limits of rapid charging protocols.
Peak Analysis
Position and height of the signature depend on the amount of plated metal present. Analyzing the lithium stripping peak allows engineers to quantify the efficiency of the plating and stripping process. This calculation helps evaluate the risk of dendrite formation under fast charge conditions.
Temperature Impact
Chemical kinetics of the stripping reaction are highly sensitive to operating temperatures. At low temperatures, the lithium stripping peak shifts to higher potentials, showing that the dissolution process is kinetically hindered. This shift indicates that the plated lithium is more difficult to remove safely.
Life Prediction
Continuous tracking of these signatures helps predict the onset of rapid cell degradation. When the lithium stripping peak diminishes over cycling, it suggests that plated lithium is being converted into inactive dead lithium. This transition represents a direct loss of cyclable lithium inventory.
