Meaning
Lithium plating occurring in a state of insufficient electrolyte wetting refers to a failure mechanism where metallic lithium deposits on the anode surface due to localized ion starvation. Dry-out lithium plating emerges when the pores of the separator or the active material layers lose contact with the liquid medium during high rate discharge or rapid charge cycles. This condition creates high resistance zones that force ion deposition at the solid-liquid interface rather than intercalation within the lattice.
The process accelerates battery degradation by creating non-conductive pathways that isolate active lithium.
Charging Mechanics
Elevated current density across dry regions forces ions to bypass standard transport routes. Electrodes operating under these starved conditions experience non-uniform potential distribution across their surface area. Small patches of the anode become sites for dendrite initiation because the solid electrolyte interphase layer ruptures to accommodate the irregular flux of incoming ions.
Operational Consequence
Thermal instability increases when these deposits build up during repeated cycling. Internal shorts grow between the electrodes as the metallic structures penetrate through the pores of the separator. Capacity loss follows these physical changes since the lithium metal sequestered in the plating layer no longer participates in the electrochemical cycle.
Assessment Protocol
Diagnostic voltage profiles provide evidence of these internal physical changes by tracking the characteristic shoulder of the potential curve during the end of the charging phase. Measurement equipment monitors the sudden rise in overpotential that precedes mass transport limitation. Technicians verify the presence of this degradation by inspecting the anode morphology after cell autopsy.
Constant current pulses help identify the exact stage where ion transport fails to keep pace with the applied electron flow.
