Why can a battery get thicker? Three simple reasons:
- Breathing When SoC goes up or down, the anode and cathode gently
expand and shrink (like lungs).
- Irreversible swelling Over life a thin SEI “crust” grows and
adds permanent thickness (lower SoH → more swelling).
- Compression Squeezing the stack pushes back.
- Cylindrical: the metal can fixes thickness; you can't tune the squeeze.
- Pouch/Prismatic: you can clamp it (springs/pads). More squeeze = less empty space.
- SoC drives breathing
- SoH lower = more SEI swelling
- Cylindrical toggle fixed-thickness can
- Compression clamp force for pouch/prismatic cells
👉 Move the sliders and watch layers and total thickness respond.