Previouly we have looked at the fundamental differences between the power and energy cells, but why is there a Power versus Energy Cell Cost difference? Typically, energy cells cost ~80-100 $/kWh in 2024 and power cells ~150-300 $/kWh. Although, there are some exotic power cells that cost ~$600/kWh.
Let’s think about the factors that make power cells more expensive:
- more refined chemistry particle size
- thicker current collector
- more copper and aluminium / kWh
- thicker separator
- greater volume of separator tends to be used, and more electrolyte tends to be used as there’s
- typically more separator (electrolyte reservoir) contained in a power cell
- higher porosity separators are selected for power cells.
- more connections between electrodes and tabs
- more complex assembly, more material cost, more welding events
- high conductive carbon content
- addition of carbon nanotubes will increase cost
- smaller cell capacity
- smaller cells result in a higher overhead
- smaller production volume
- purchasing volume is directly related to $/kWh
- lower yield
- power cell electrode can suffer lower yields than thicker energy electrode, as thin electrode are a challenge for many coaters
- coating defects (agglomerates, fisheyes, drag lines, etc.) can become very pronounced in thin films
This post has been built based on the support and sponsorship from: Thermo Fisher Scientific, Eatron Technologies, About:Energy and Quarto Technical Services.
Perhaps the biggest factor is production volume or buying volume. Some of the largest producers of HEV battery packs such as Toyota will be buying enough kWh of cells overall that the cost/kWh is likely to be a lot lower than smaller manufacturers in the EV market.
High power (>20C charge / discharge rate) cells used in HEV vehicles tend to be for a small total energy ~0.5 to 3kWh. This also means that the cell capacity will be smaller (~6 to 20Ah) and hence cell assembly, case, tabs, formation, ageing and logistics will be a larger percentage / kWh.
In some of the latest BEV’s we are seeing the use of 100 to 300Ah cells and hence the costs/kWh are much reduced.