Will sodium ion batteries challenge lithium?

[Stan]

[Stinsy]

Nice video. The guy clearly knows his stuff.

I think I’ve said before the BEV batteries are going in an interesting direction. I keep reading in MSM about future BEVs having 600-miles of range from a battery half the size/weight of the NMC batteries currently used. However the reality is that LFP is becoming the standard in base model BEVs even though it is less energy dense than the existing technology. The logic of: “NMC for mobile applications where size/weight are critical, LFP for fixed applications” seems to have been overturned.

Sodium batteries are even less energy dense. Which makes packaging an efficient 200-mile BEV very difficult indeed, looks like they’ll be suitable only for 50-mile city cars. My feeling is that this presents a psychological barrier to BEV ownership. Plenty of people only use their car for shopping/school run/local errands. A 100-mile BEV is more than they need, but they won’t buy one because it can’t conveniently do a 400 mile journey that they’ll never do in reality but like to think they might one day. Whereas a 200-mile BEV (with rapid charging capability) will convert these people. They’ll still never drive more than 50 miles in a day, but they will actually buy a BEV. A bit like that deep-sea divers watch that has never gotten less than 1ft below the surface of the hotel pool.

I can see sodium batteries being very suitable for stationary applications. But as I say: I thought that about LFP!

[Stan]

Hi Stinsy
I think that on line 5 you mean LFP for static applications.

[dan_b]

How does the energy density of Sodium-ion compare to Iron Phosphate, and NMC?
And how does it compare cost-wise?

I guess the issue with "small car EV" is that you have a much smaller physical platform in order to fit the cells. The breakthrough with IronPhosphate as far as I could tell is that the energy density got good enough so that it could provide sufficient kWh in larger cars by filling the battery pack space that, in lower range versions, was basically empty, and so could still get 50-60kWh of cells in there.

Feels like you might not be able to do that with Sodium-Ion to benefit from the lower cost/kWh unless you're making cars with low ranges again - back to the OG Nissan Leaf type range? Which then puts you in the "City Car" /2nd car bracket, rather than "just a small family hatch that can still do everything"?

[Stinsy]

Hi Stinsy
I think that on line 5 you mean LFP for static applications.

TY. Fixed it.

[AlBargey]

I'm not sure the massive voltage range of Sodium batteries which can discharge voltage down to 0v will be that useful as a drop in replacement for any of our current battery technologies used over the last 50 years, without a whole new range of inverters?

But I do like the other problems they could solve with Lithium and lead.

[Mart]

How does the energy density of Sodium-ion compare to Iron Phosphate, and NMC?
And how does it compare cost-wise?

I guess the issue with "small car EV" is that you have a much smaller physical platform in order to fit the cells. The breakthrough with IronPhosphate as far as I could tell is that the energy density got good enough so that it could provide sufficient kWh in larger cars by filling the battery pack space that, in lower range versions, was basically empty, and so could still get 50-60kWh of cells in there.

Feels like you might not be able to do that with Sodium-Ion to benefit from the lower cost/kWh unless you're making cars with low ranges again - back to the OG Nissan Leaf type range? Which then puts you in the "City Car" /2nd car bracket, rather than "just a small family hatch that can still do everything"?

Hi Dan, been trying to find more info on this, but every article I found has different numbers. For my own ponderings I'm going to use (for now) a rough figure of 100Wh/kg for sodium, 150 LFP and 200 for NMC. But that's just for low rough calcs in my head. In fact the vid itself has the sodium batts suggesting 160Wh which is at LFP levels. But cost is important, and the more you pay, the higher the figures, so 50% more for each is entirely possible.

An interesting point mentioned in the vid, is that only about 1% of batts will be sodium by 2030. I think that is linked to the fact that lithium prices have tumbled the last year, reducing the cost benefits of the admittedly cheaper sodium batts. So perhaps the best news here is that sodium batts offer a good enough alternative to LFP, if the price of lithium goes up, thus preventing another price spike, as supply/demand can shift between the two, to help ration out available materials.

Again only personal ponderings, so plenty of room for error, but if Tesla can get about 60kWh of LFP's in the model 3, then I'd hope that even a relatively small vehicle could fit 40kWh, perhaps 30kWh+ of sodium ion. So for a smaller/lighter vehicle 100+ miles of range should be doable.

Also, the learning curve for batteries, with each doubling of production seems to be around 10-15% in cost, and ~5% in energy density, so things look very bright for the future.