Is Sodium Ion about to hit mainstream

[T1 Terry]

CATL recently announced their first supplies of Na+ (Sodium Ion) batteries for next mth. That belief that it was yrs away before they reached anything that was comparable to LFP may have just been shattered.


My question is, would you choose an EV with comparable range that used Na+ cells, or stick with NMC or LFP chemistry batteries?

T1 Terry

 

[Everest]

What is their power to weight ratio and longevity?

 

[Alb]

I wouldn't move to the technology just for the sake of it but it will likely become common in time.
What we have at the moment isn't broken so I'm in no rush to fix it.

 

[T1 Terry]

I wouldn't move to the technology just for the sake of it but it will likely become common in time.
What we have at the moment isn't broken so I'm in no rush to fix it.

It is broken, The two choices at the moment are:
Ternary chemistry cells like NMC (Nickel Cobalt Manganese) and NCA (Nickel Cobalt Aluminium) don't function all that well in the cold, -20°C will result in a 60% to 80% capacity loss .... this becomes more apparent as the cycle life increases resulting in serious loss of range in the cold as the vehicle battery ages ... rapid charging ages them much faster than home charging.
They also do not meet the Chinese thermal runaway criteria and will be banned from use in new Chinese cars sold to the local market.

LFP will work discharging down to -20°C, but they should not be recharged at anything below 0°C or risk both capacity loss and not achieving a full recharge.
They are far better at thermal stability and don't suffer thermal runaway to the point that they pass the Chinese criteria for the domestic vehicle EV market.

Where the temps drop below -20°C, Sodium ion is the better chemistry, have the least capacity loss and have by far, the longest cycle life. They do not suffer thermal runaway and pass the 120km/h barrier crash test, Ternary cells most definitely won't and I don't believe LFP have been tested to this sort of collision impact to find out just what would happen ....

T1 Terry

What is their power to weight ratio and longevity?

Power to weight is equal to the commonly used LFP chemistry, 175Wh/kg and a much longer cycle life, particularly if fast charged. They do not require special battery heating in the cold, down to -40°C ..... which I just learnt, is the same as -40°F .... who knew (well, probably lots of people).
The other promising thing is they are very young in the development time span, so things can only improve as time goes by .......

T1 Terry

 

[Everest]

I knew that

 

[T1 Terry]

I knew that

Glad to hear you are keeping yourself well informed

T1 Terry

 

[Everest]

You're making it all sound very rosy. But what about maximum charge rate of SIBs compared to NMC?

 

[Everest]

Glad to hear you are keeping yourself well informed

rather, I was taught that at school and that's a very long time ago, but fortunately the C and F scales haven't changed much in all that time!

 

[T1 Terry]

You're making it all sound very rosy. But what about maximum charge rate of SIBs compared to NMC?

The CATL Na+ will charge at 5C without a problem, all day every day, NCA at around 2C to 80% but degrade due to heat generation internally over time, NMC at 1C to 1.5C to 80%, but again, continual fast charging will shorten cycle life.

Good quality LFP, 3C to 5C, but 1C can be pumped in to around 95% SOC .....

C rating is the parallel cell capacity, so a 100Ah Na+ cell, can be charged at 500 amps till the voltage reaches 4.3v, close to 95%, then slowed down to stop the cell going over the 4.3v, probably around 15 mins to fully saturation charged, but 10 mins or less, depending how deeply discharged the cell was, will reach around 95% SOC

Do not try this at home with any of the other three chemical lithium batteries, 4vdc max for LFP but drop down to 3.65v for the constant voltage stage to get the cell up to saturation charged 100% capacity

Let me know if you attempt that sort of charging with NMC or NCA cells, I wanna watch from a safe distance, so please set up a camera so I can watch it from my laptop

T1 Terry

 

[Everest]

5C sounds impressive if true... how many CATL shares do you own

 

[T1 Terry]

5C sounds impressive if true... how many CATL shares do you own

As if, I doubt you can even buy shares in CATL, Chinese companies are a bit funny like that

T1 Terry

 

[Bam Bam]

CATL recently announced their first supplies of Na+ (Sodium Ion) batteries for next mth. That belief that it was yrs away before they reached anything that was comparable to LFP may have just been shattered.


My question is, would you choose an EV with comparable range that used Na+ cells, or stick with NMC or LFP chemistry batteries?

If it is better or the same in every way as LFP (and better in all but weight over NMC) I would go for sodium.

• Better cold weather performance
• Better for the environment
• Longer lasting
• Cheaper (presumably)

But will it achieve all those things? Let's hope so!

 

[GaryMG4]

If it is better or the same in every way as LFP (and better in all but weight over NMC) I would go for sodium.

• Better cold weather performance
• Better for the environment
• Longer lasting
• Cheaper (presumably)

But will it achieve all those things? Let's hope so!

I think the recent drop in Lithium prices killed the 'cheaper' advantage causing some companies to either quit or put on hold their development. source Matt Farrell - Undecided.

 

[Rolfe]

LFP will work discharging down to -20°C, but they should not be recharged at anything below 0°C or risk both capacity loss and not achieving a full recharge.

That would be 0°C battery temperature rather than 0°C ambient temperature, though, and you can always run a battery heating cycle.

 

[Bam Bam]

That would be 0°C battery temperature rather than 0°C ambient temperature, though, and you can always run a battery heating cycle.

Absolutely, but that is using up some power that wouldn't be necessary for the sodium chemistry, meaning that there will be much less of an efficiency drop in winter.