"Salt" Batteries are FINALLY Here?! Sooo should you use them?

Now these two batteries here look about the same, right?

But while they both can provide portable energy for your laptop, vacuum cleaner or for example

cordless power tool; their inner composition it totally different.

You see this one is made up of lithium and this one is made up of sodium.

And yes; this is very exciting because while lithium is a scarce resource that is also

quite pricey, sodium is not rare and thus also a lot cheaper.

I mean normal table salt aka sodium chloride is made up of around 40% sodium.

And for months now I have seen videos on YouTube talking about that such Salt batteries aka

Sodium-ion ones will be the future of battery technology; but no one actually tested a real

one yet.

So I was very excited to find these cells for sale on AliExpress and I know what you're

thinking; But no, they are not fake.

And in this video I will show you exactly why I think they are real and more importantly

do a bunch tests in order to ultimately tell you whether you should from now on, only use

these salt batteries instead of common lithium-ion ones.

Let's get started!

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Now first off when looking at these two batteries, there is obviously no way to tell whether

this one is really sodium based.

One possible way to find that out though is of course cutting it open and looking inside.

But because I tried the exact same thing in a previous video and had no idea what I was

looking at because I am not a chemist; we should probably instead focus on an electrical

method.

One of them is called charge/discharge curve meaning we charge and discharge the battery

while monitoring its voltage and flowing current.

So let's do just that starting with the lithium battery by firstly adding tabs to its plus

and minus pole and then checking its datasheet to find out how it wants to get treated.

And it seems like its standard charge is 1.25A up to a voltage of 4.2V and for the discharge

we

can do a maximum of 20A down to 2.5V; but I wanted to keep it low and thus settled for

2.5A. With that in mind I set up my Battery Tester,

hooked up the battery, adjusted the current and voltage values in the software and began

with the charging process which after around 2 hours gave me this curve.

So next it was discharge curve time; which after around 1 hour looked like this and if

we put them side by side then we can see a very typical lithium based curve which not

only applies to such lithium-ion cells, but also LiPo ones and big Lithium Iron Phosphate

ones.

So next let's compare it to the supposedly sodium ion batteries for which I also hooked

one up to the battery tester and set its charging voltage and current to 4V and 1.3A just like

the datasheet recommends it and its discharge current to 2.6A down to this time 1.8V.

And after once again waiting for a few hours, I was greeted with these curves here which

without a doubt look quite a bit different than the lithium-ion ones and do correspond

with sodium-ion curves you can find in scientific reports which is enough prove for me.

But which curve is now better, you might ask?

Well, the main big difference is that the lithium battery comes with a narrower voltage

plateau where the battery spits out its energy which is around 4V to 3.4V.

The sodium one on the other hand has a wider one between 3.9V and around 2.1V

This has the advantage that you can more easily determine how much charge is left in your

battery, while lithium based ones often have to keep track of how much current goes in

and out of the battery to determine its State of Charge.

But then again when you got a load that needs a constant power, then its is definitely easier

to work with a more stable voltage because then the current also stays around the same.

With a more decreasing voltage though, the current has to constantly rise to get the

same output power and thus your power electronics have to be designed this way which can be

a bit more expensive.

So yeah, both curves have their pros and cons; but what is a definite disadvantage is that

while both batteries come with the same size, the sodium one can only deliver around 4.06Wh

of energy while the lithium one can do 8.7Wh which is more than double.

Of course when digging a bit online you can find sodium cells with slightly higher capacity,

but certainly not as high as lithium based batteries at the same size.

And that directly brings me to the energy density comparison for which I checked the

volume, weight and price of one sodium-ion cell and added those information to my battery

comparison chart.

And as you can see sodium-ion can only barely rival lithium iron phosphate when it comes

to energy density while being quite a bit more expensive.

But I bet that will soon change due to the low price of the material and is currently

only so high because it is a new technology that is not quite in mass production yet.

And speaking of new technology; there also do not exist dedicated charging ICs for sodium-Ion

batteries yet which are definitely mandatory though because of the different charging voltage.

But the good news is that with an ordinary LM317 adjustable voltage regulator, you can

pretty easily build up a crude constant voltage constant current charger according to the

schematic given in its datasheet.

With this resistor value we should get a maximum of 1.3A and with this resistor voltage divider

an output voltage of 4V which according to my tests was all pretty close and thus suitable

for my sodium-ion battery.

And if you want to put multiple cells in series in order to form a powerful battery pack,

then you also need a Battery Management System aka BMS to keep each individual cell safe

from overcharge and over discharge which now also needs to work with other voltage levels.

But thankfully there appears to already exist a commercial version.

So yeah, new technology obviously comes with some challenges; but for now let's switch

back to our raw cells here and the very important question how fast we can charge them up and

discharge them.

Now when looking in the datasheets then we can easily figure out that the max values

are way bigger for the lithium based battery.

To prove this, I powered up my new battery 

tester which can measure  the internal DC resistance

of a battery, by basically comparing how much its voltage drops when more and more current

flows.

After doing this test with both batteries you can see that the sodium one features a

33% higher internal resistance, meaning that due to its chemical structure it produces

more heat when more current flows.

That obviously limits its input and output power capabilities; but while that sounds

bad those values are still very close to those of lithium iron phosphate batteries and you

know, those get used as energy storages for houses and also in electric cars.

But while this chemistry does not allow for maximum power, it certainly improves the safety

aspect.

I mean when looking up lithium-ion videos on YouTube, then there are plenty where fire

and explosions are involved including my own one from almost 10 years ago.

But when browsing through  the sodium-ion datasheet, 

then you can always read that no fire or explosion

took place which I know would definitely be interesting to test on my own.

But honestly speaking I was a bit too scared to do that.

So instead I recommend you to watch this video which summarized, ended with the cells flying

around but not creating an explosion or fire.

And last but not least we got the topic of cycle life meaning how often I can discharge

and charge up the battery before it is losing capacity.

And according to the datasheet the sodium battery does 1000 cycles while maintaining

85% of its capacity, while the lithium battery only comes with 60% after 250 cycles which

is a huge difference.

And with that being said, I think we discovered the most important advantages and disadvantages

when it comes to this new battery technology.

So do I think we should now all replace all of our lithium-ion batteries?

Well, definitely not because  I feel like sodium-ion 

is electrically more similar to lithium iron

phosphate and I hope to see it sooner or later become its replacement so that we finally

can have a more environmental friendly battery.

So time to play the waiting game; but while doing that, feel free to check out some of

my other videos or my Patreon in order to keep this show going.

As always don't forget to like, share, subscribe and hit the notification bell.

Stay creative and I will see you next time.