Predictive Modeling of Creep Driven Pore Growth under Cyclic High Temperature Tooling Loads
Predictive creep modeling quantifies elevated temperature pore evolution in solid state cell tooling to establish precise hold times and prevent yield loss.
Void Coalescence
Meaning
Microstructural failure mechanisms describe the growth and merging of microscopic internal voids within metallic lithium anodes during extended stripping cycles. Void coalescence creates macropores and structural vacancies that concentrate current density, leading to localized dead lithium formation and premature cell shorting. The mechanism governs stripping current density limits, stack pressure requirements, and cycle life longevity in solid-state lithium metal batteries.
It ceases to apply when compressive stack pressure forces creep deformation that closes microvoids faster than stripping vacates lattice sites.
Failure Kinetics
Vacancies formed during high-current lithium stripping migrate and merge into large structural voids at the solid electrolyte interface. Uncontrolled void coalescence destroys continuous physical contact between the metallic anode and the solid separator membrane. Localized loss of contact forces remaining contact spots to carry disproportionately high current densities, accelerating dendritic growth.
External stack pressure suppresses void merging by driving plastic creep of metallic lithium into newly formed vacancies.
Current Distribution
Non-uniform interface contact alters localized electrical fields and ionic transport paths across active separator surfaces. High current concentration at contact edges accelerates localized interface degradation and cell capacity fade.
Porosity Growth
Structural vacancy accumulation increases subsurface porosity within metallic lithium foils during fast discharge pulses. Unchecked porous network expansion causes structural collapse of the anode-electrolyte interface.