Modeling Stack Pressure Effects on Interfacial Void Growth in Solid-State Lithium Anodes
Maintaining 5 MPa stack pressure suppresses lithium void growth during high-rate stripping while active spring packs prevent separator fracture.
Current Channeling
Meaning
Non-uniform current density distributions diverge from theoretical planar conduction pathways across battery electrode interfaces. Structural variations in electrode coating thickness or localized electrolyte depletion force electrical current into narrow high-density paths. Under high C-rate charging conditions, current channeling accelerates degradation by generating localized overpotentials and hot spots.
Concentrated current flow triggers premature lithium plating on negative electrode surfaces even when average cell voltage remains within safe operating limits.
Imbalance Driver
Local porosity fluctuations inside porous electrode structures create non-uniform ionic resistance paths through the liquid electrolyte. Areas with higher local porosity or superior wetting conduct significantly higher ionic currents than adjacent dry or dense regions. Concurrently, tab positions induce electron current concentration near current collector connection points.
These combined ionic and electronic pathways cause severe current density gradients across the active material area.
Degradation Pathway
Accelerated electrolyte breakdown and localized high current density promote dendritic lithium formation at high-flux regions.
Design Mitigation
Multi-tab electrode architectures and optimized current collector thickness equalize current distribution across large-format pouch cells. Thermal imaging and localized impedance spectroscopy map current density variations during cell development and validation testing. Manufacturing specifications enforce strict tolerances on coating weight distribution to minimize localized current hot spots.
Homogeneous current flow extends cycle life by preventing localized cell aging and thermal instability.