Battery pack Ragone plot is power density versus energy density. There are a number of key battery metrics and this one is great to see where a design sits on the Power vs Energy Density Curve.
Note that the power is the peak power of the pack available for 10s. You could also plot the power as continuous.
In simple terms:
- Moving to the right on the x-axis is increasing in energy density
- Moving up the y-axis is increasing the power density
There are a number of factors that make it difficult to engineer a pack with very high power and high energy density.
The main factors are:
- Power versus Energy density cells
- thinner anode and cathodes increases power and decreases available energy
- Cooling more demanding in high power packs and hence increased mass and volume to package (cooling options)
- Thicker busbars – current carrying capability is proportional to the cross-sectional area
- High power = High currents => larger fuses and contactors