Quantifying Localized Lithium Plating Onset via Differential Voltage Tracking
Differential voltage tracking identifies localized lithium plating onset by detecting subtle slope shifts during charge and characteristic dV/dt relaxation plateaus.
Copper Foil Lithium Deposition
Meaning
Secondary electrochemical reactions on the negative current collector during overdischarge or extreme fast charging degrade cell health. Copper foil lithium deposition occurs when lithium ions receive electrons and form metallic lithium directly on the surface of the copper substrate instead of intercalating into the active carbon structure. This phenomenon leads to capacity loss and poses safety risks if dendrites penetrate the separator, making foil selection and surface treatment critical for high power applications.
Electrode Interface
Surface conditions of the negative electrode current collector influence how metal ions behave under high current densities. Standard cell operations rely on intercalation, but copper foil lithium deposition happens when the local potential of the anode drops below zero volts against lithium reference. This shift forces the metallic phase to nucleate on the foil.
Safety Consequence
Metallic build-up on the current collector creates structural vulnerabilities within the battery. Once copper foil lithium deposition begins, the highly reactive metal can consume the liquid electrolyte to form a thick resistive layer. This growth increases internal resistance and heat generation during subsequent cycles.
Mitigation Strategy
Manufacturing controls and charging protocols are designed to restrict the conditions that trigger metallization. Advanced charger algorithms limit current at low temperatures where copper foil lithium deposition is most likely to proceed. This control strategy extends the operating life of high power battery systems.