I'll rehash this post I posted awhile back on the pls forums....

I'll rehash this post I posted awhile back on the pls forums.

"Sodium battery cells potentially cheaper at scale vs lithium we all know this.
But is the pack cheaper???
After watching tesla investor day they mentioned that they have an xl mega pack which is the largest you can fit transporting on the back of a truck until you need special permits for road closure and transporting over weight objects.
These permits can cost in the thousands to tens of thousands.
So obviously it is cost effective to keep these packs this size they went on to say this is the largest they will make.

A rough guide for energy density for different chemistrys.
Tesla 4680 275 wh/kg
Lfp 200 wh/kg
Sodium 150 wh/kg

So if you make a mega pack with the 4680 cells the energy is double that of sodium therefore you would need to make two mega packs to account for the price of one.

If you get your sodium cells at less then half the price you'd think your of to a good start but you will have to pay for the rest of the second pack, you would be paying double on the following.

Copper wire, electronic components, battery management systems and cooling systems.
The shell,casing and construction of the second pack frame.
Labour costs and higher factory floor print.
Transporting cost
On site crane and site preparation cost
The cost of additional land space to house the packs.
Additional connection costs from pack to pack as there will now me more
And possibly other costs suppliers, staff ect.

So while sodium has its limitations in the ev industry due to weight constraints
perhaps it will aslo have limitations in stationary storage due to energy density and transporting and additional costs??"

Another thing to add would be the cycle life if lfp have double that of sodium ion then the sodium cells would have to be replaced half way through the life time of the project to keep in line with lfp.
This pack would have to be redesigned with removable cells in mind which would be quite a substantial cost in swapping the cells out or replaced with entirely new packs which would not be ideal long term..

I have heard of some high performing sodium ion batterys containing rubidium with in the chemistry which is very expensive so the sodium is cheap but other elements in cathode and anode may not be.

Where I can see sodium ion playing a roll in ess is mostly small to mid storage solutions where some of the factors above like weight, volume and peak feasibility don't apply, eg a cheaper home storage system or back up energy systems for data centres ect.

Also have to keep in mind looking forward are further advancements in lithium batterys aswell as sodium ion on the ess debate

Gltah cheers