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.
Porosity Volume Fraction
Meaning
Microstructural volumetric metrics quantify the ratio of void space to total physical volume within porous battery electrodes and polymer separators. Porosity volume fraction determines effective ionic conductivity within liquid-filled pore networks, active material loading capacity, and total electrolyte retention. The parameter governs ionic transport resistance, electrolyte wetting speed, and volumetric energy density calculations during electrode slurry formulation.
It stops applying once full dense consolidation eliminates open pore networks or when materials transition into non-porous solid states.
Transport Impedance
Liquid electrolyte filling open void spaces creates conductive ionic channels between active material particles and separator boundaries. Balancing porosity volume fraction requires trade-offs between high volumetric energy density and fast lithium ion transport through liquid channels. Low void volume increases volumetric energy storage but restricts liquid diffusion, leading to severe rate capability penalties at high discharge currents.
High void volume lowers cell internal resistance but reduces total active energy storage per unit volume.
Coating Density
Mechanical calendering reduces internal void space to achieve target compaction densities on current collector foils. Precise roll nip control sets the final void volume fraction within strict percentage limits across full coating production runs.
Electrolyte Absorption
Total void volume determines the precise volume of liquid electrolyte required to achieve complete pore saturation during cell filling. Excess void space increases cell weight without adding electrochemical capacity.