Differential Capacity Quantification of Non Reversible Plated Metallic Lithium Microstructures
Differential capacity sweeps at C/20 isolate non reversible plated lithium by separating reversible stripping peaks from active lithium inventory loss.
Anodic Stripping Peak
Meaning
Current maxima recorded during the electro-oxidation of deposited metals represent the primary measurement for quantifying trace elements on electrode surfaces. An anodic stripping peak emerges when the potential sweeps in the positive direction, causing the previously reduced species to oxidize and strip back into the electrolyte. The height of this peak relates to the concentration of the analyte, while the position identifies the specific metal present.
Electrochemical Response
Voltammetric sweeps provide the raw data used to characterize electrode reactions. Analyzing the anodic stripping peak helps identify the onset of lithium plating in lithium-ion batteries. When lithium ions cannot intercalate quickly enough during fast charging, they deposit on the graphite anode as metallic lithium.
The subsequent discharge or stripping scan reveals a distinctive anodic stripping peak that indicates the presence of this unwanted phase.
Detection Limit
Electroanalytical sensitivity depends on the phase of the working electrode and the rate of the voltage scan. While a sharp anodic stripping peak provides clear evidence of surface metallic lithium, minor plating events often remain obscured by background capacitive currents. Adjusting the scan rate or using differential pulse methods improves the resolution of these electro-chemical signatures.
Sourcing teams rely on these measurements to evaluate how cell chemistry performs under rapid charging regimes.
Sourcing Utility
Battery cell evaluation requires verification of anode stability under extreme operational stresses. Specifying an acceptable threshold for any anodic stripping peak in test protocols ensures that purchased cells resist degradation under fast charging conditions.