Cell Design

Cell design requires inputs from chemistry, electrical, thermal and mechanics.

Electrode Stack

The core building block of any battery cell is the stack:

  • Cathode
    • current collector
    • active cathode
  • Separator
  • Anode
    • active anode
    • current collector

Within this sandwich we must include the electrolyte. Each of these elements can be broken down further, but initially it is worth thinking about the fundamentals of this layered sandwich.

cell electrode thickness

Effect of Electrode Thickness on Cell Energy Density

In Li-ion batteries, the cathode thickness will heavily influence the energy density of the cell. A thicker cathode means there will be more cathode active material in the electrode. This increases the capacity of the electrode and hence increase the energy density of the cell.

Power versus Energy Cells

Comparing power versus energy cells we see there are some fundamental differences. A high energy cell will have better volumetric and gravimetric energy density at the expense of the ability to deliver a high current. The power cell will have a low internal resistance and will be optimised to deliver current over energy density.