INNER ARCHITECTURE • SANDWICH

Electrode, separator, electrode

▮ electrode | ░ separator | ▮ electrode

In the sandwich geometry, the electrodes face each other across a thin porous separator soaked in electrolyte. The separator blocks electrons but lets ions through, so ions cross the layer thickness.

Capacity scales up by stacking more layers or using thicker electrodes.

INNER ARCHITECTURE • IN-PLANE

Side by side, no separator

▮ electrode ·· gap ·· electrode ▮

In an in-plane (coplanar) device, both electrodes sit on the same surface, separated by a small lateral gap. That gap, filled with liquid, gel, or solid electrolyte, replaces the separator entirely.

Both electrodes can be patterned in a single step, which suits chips, films, and printing.

SANDWICH VS. IN-PLANE

Two ways to arrange the ions' trip

Ion path Sandwich: through the separator · In-plane: across the lateral gap

Build Sandwich: assemble and stack layers · In-plane: pattern both electrodes at once

Scaling Sandwich: add layers upward · In-plane: add fingers sideways or grow taller

Best for Sandwich: cells and modules · In-plane: chips and flexible films

A thin in-plane device holds little material per footprint unless its electrodes grow tall.

UNIT 14 STUDY COMPLETE

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Ready for the Fab Challenge?

You've covered stacked electrodes with a separator, or side-by-side electrodes with a gap.