Meaning
Develops in the interior regions of thick porous electrodes during rapid charge or discharge events when ionic depletion exceeds bulk liquid transport rates. Depletion of lithium ions within microscopic electrolyte channels causes pore starvation and sharp overpotential escalation. High C-rates and low operating temperatures accelerate liquid phase reactant exhaustion inside micro-porous electrode networks.
Boundary conditions are reached when local ion concentration drops to zero, triggering parasitic side reactions.
Mass Depletion
Ion flux through complex pore channels cannot match electrochemical reaction rates required at high charge currents. Concentration profiles collapse near the current collector foil, creating localized dry regions devoid of charge carriers. In pore starvation scenarios, potential drops increase dramatically as resistance to charge transfer approaches infinity inside empty electrolyte pores.
Cell terminal voltage drops prematurely before available capacity in active particles is fully utilized.
Plating Risk
Severe ion depletion alters local interfacial equilibrium potential at graphite anode particle surfaces. Negative potential shifts promote metallic lithium deposition over intercalation, increasing short-circuit safety risks.
Specification Limits
Cell designs must constrain active layer thickness and tortuosity parameters to maintain ionic transport under peak load conditions. Procurement documents for fast-charging power cells define maximum coating weight limits to prevent electrolyte depletion across operating temperature ranges. Cell designs failing pore transport criteria experience rapid capacity retention loss during high-rate cycling.
Quality audits check electrolyte fill volume and wetting speed to eliminate starvation hazards.
