Supercapacitors vs batteries. Capacity.

[liveforphysics]

Every LIB has the intrensic supercap properties already and always has.

Obviously, not all of them, or they wouldn't behave differently.

Youve created a double layer supercap the moment you wind up the porous anode and cathode layers of foil and wet them out with an organic non-electrically conductive dielectric fluid which can be polarized by surface charge e-fields.

From the first commercially successful lithium ion batteries, the battery has also has an intrensic super cap by virtue of it's design using high sure area materials wetted by dielectric as an aspect of normal construction.

 

[fechter]

Maybe it doesn't matter so much what they call it.

If it has 1,000,000 cycle life and the cells can be shipped at zero volts, it is not like your typical battery.

 

[Buk___]

...

From the first commercially successful lithium ion batteries, the battery has also has an intrensic super cap by virtue of it's design using high sure area materials wetted by dielectric as an aspect of normal construction.

And yet, they -- ie. Lithium Ion batteries and lithium Ion supercapacitors -- have different names, ratings and performance, so they aren't "the same" are they.

And indeed, there are clever people spending a lot of time and money on try to "Hybridizing battery and capacitor materials to construct lithium ion capacitors (LICs) ... to bridge the gap between high-energy lithium ion batteries and high-power supercapacitors."

Now doesn't that sound a lot like what I was trying to talk about, before you interjected a piece of irrelevant information that everybody knows, as if it was some startling new incite that in some way renders what I said, null & void?

 

[billvon]

It's going to be mildly amusing to watch the naysayers here backtrack when this turn out to be exactly what they say it is.

That would be great, but unlikely.

I designed my first lithium ion battery pack back in 1996; I used 1300mah 18650's (the best cells on the market at the time.) Since then I can't count the number of times I've seen "breakthrough" batteries announced. And yet almost all the progress since then has come from incremental refinements to that lowly 18560.

When you see 600 breathless pronouncements about the latest super energy dense, very cheap, million cycle battery, just to see them all peter out into nothing, it's hard to get excited about pronouncement #601.

 

[liveforphysics]

There is a huge difference that's why the capacitor, including LiC capacitors have poor energy density, it's because they aren't moving the lithium ions, just using their surface potential to milk that V^2 relationship in capacitors.

Lithium Titanate cells, like you see discharged in his cell and resistor video do migrate lithium ions from anode to cathode discharging to keep the voltage up, and that makes them a battery, but they are intrensically also a supercap in parallel with that Titanate battery, just as every cell has its own inescapable self-capactence.

Definitely a lithium ion battery. Definitely a supercap. Sharing the same foil current collectors.

 

[TheBeastie]

Maybe it doesn't matter so much what they call it.

If it has 1,000,000 cycle life and the cells can be shipped at zero volts, it is not like your typical battery.

Exactly, even if its 500,000 or 100,000 cycles that's pretty different.
The main other thing to note is its about 2.5Wh per cell (maybe a bit higher?) while 18650s are average 10Wh so 4 times more.

So its not the most amazing thing in the world, it fits perfectly in a space where it might be useful in specific areas.
If it was made up baloney to sucker investors or something they would claim the full 10Wh like a regular 18650.

 

[liveforphysics]

A couple Wh per cell is what you would get in a Titanate 18650 optimized for cycling.

A couple Wh of energy storage from any kind own type of supercap or Li voltage boosting cap from something 18650 size would require some new material science I've not yet seen, and still would not discharge with the textbook profile of a Titanate cell.

 

[jmetric]

I agree with most of the posts. I tried to replace a 1000HP 400V battery with Maxwell ultracaps. Using the Maxwell capacitor estimator spreadsheet called "Tecate_Constant_Power_Sizing_Tool_v1.0.xls". It was ridiculous how large the system turned out to be.
If you need the power to be the same at the near discharge point than the charged voltage needs to be nearly 2X the discharged voltage.
and the discharged voltage is 50% of the charged voltage. So if you need a 300V supply nearly empty, then you need to start with a 600V capacitor accumulator.
To give you a comparison.
I built this system out of 84 6S Lithium Cobalt modules(inside the rightmost green case), it provided 1000HP and 400Vcharged and 300V sag and 8.2kWhr cost about $10,000 and weighed about 150lbs. you can see it fit in a large suitcase.

The equivalent 1000HP that didn't sag below 300V in Maxwell Ultracaps was 650lbs, about six of those large suitcases and was only 1kWH and costs nearly $30,000

 

[liveforphysics]

Thank you for sharing John! You are a legend!

 

[Buk___]

When you see 600 breathless pronouncements ... it's hard to get excited about pronouncement #601.

I understand. I stop reading pronouncements when the start getting "breathless", and generally do not give marketing hype much credence. Nor do I expect to see the conclusions I read in the latest scientific papers to make it to the commercial world any time soon.

But if this is a con, it's a very strange one.

A raft of very 'production ready' looking prototypes; a clearly defined set of performance claims; (projected?) pricing that is neither so low as to make it implausible, nor so high as to be out-of-reach, pretty much in-line with other technologies with similar capacity (but lesser performance); a company that has been around for a couple of years without having (previously) said anything remarkable, nor much of anything that I can find (stealth?); no kick-starter begging bowl nor even overt signs of them seeking rounds of venture capital, but rather (the appearance of) established deep pockets already on-board.

If a con, it is hard to see the end-play.

Eventually they will have to deliver product to people who will tear it apart and report their findings, and the main players all seem to be clearly identified and resident within the reach of the law.

And when you can find scientific papers from 2,3 & 4 years ago discussing lab made hybrid LIC constructions that deliver very similar sounding performance in terms of specific energy, specific power and project cycle life; it doesn't seem such a stretch that someone with deep pockets and good knowledge has funded the move from the lab to production.

The only downside of what I see is that it would seem they are set on being very controlling of the technology -- if that's what this is. Selling it only as a part of value-add products tailored to specific markets; rather than components for others to (re)combine in interesting ways. Much less, to enthusiasts in quantities that make sense for e-bikes.

 

[billvon]

But if this is a con, it's a very strange one.

To be clear, I am not saying it's a con. They may well truly believe in their product. But again, I have seen a lot of technologies over the years fail not because they were lying about it, but because of a hidden flaw, a lack of sufficient differentiation from existing products or a list of known limitations that was not well understood by customers.

As I mentioned, I hope that's not the case and that this turns out to be a useful and successful product.

 

[Hillhater]

Assuming the Sirius pack does perform the way they claim ...3.55kWh, long cycle life, 100/300 amp discharge, etc etc... Then the only "con" is their claim that it is a "supercapacitor" based storage system with no electrochemical lithium content, when it plainly is not .

 

[liveforphysics]

The aspects that appear to be not legit:

1. Their discharge cell test was the exact V/I curve signature of Lithium Titanate.

2. Their energy density and cycling life happens with no known caps, but does fit known Lithium Titanate cells fine.

3. The encloser for packaging the cells outwardly appears to have no shot at passing salt fog or aggressive vibe profiles, but a lot like if you had to cobble something together with available LTO cells and call it some magic new capacitor tech.

 

[Punx0r]

True. Saying "we took some 10 year old design, off-the-shelf LTO cells and put them in a box" doesn't make nearly as good copy as "revolutionary 'lithium capacitor' technology solves all your previously insurmountable energy storage problems". If someone is looking for investment or juicy commercial sales, I can imagine plenty of marketing bods quite happy to play fast and loose with the technical definition of battery and capacitor.

Occam's razor slices down to the bone of truth once more.

 

[liveforphysics]

It's still not technically incorrect to call every lithium ion battery a double layer supercap that is recharged by an electro-chemical energy storage intrensic component.

Just like your motor is both a resistor and an inductor, and truly and inseparably are both of those components, so is a lithium ion battery and it's intrensic supercap.

 

[spinningmagnets]

I think it will be easier to understand how this device should be evaluated in order to properly assess how successful the engineers were, once you under stand what it was actually designed for. At first it could easily be assumed to be a replacement for lithium batteries in certain applications, encompassing some of the elements of both a chemical battery, and also an advanced super capacitor.

After a deep level of research, I believe this device might quite possibly be the most successful new development in achieving a new performance standard for transferring and storing energy from one place to...wait...did I type "energy"?...I meant money, it will set a new record for transferring and storing money...to an offshore account.

edit: After some thought, this post is a little harsh. I apologize. We should all wait to see the evidence before passing judgement.

 

[Hillhater]

It is being promototed as a storage/smoothing/backup device for domestic solar installs and critical systems.
IE :- an alternative to the Powerwall , or the LG, Samsung, BYD, etc..home battery units.
Its claimed key advantages being its ultra long cycle life and operational life, together with its fire safety.

 

[liveforphysics]

It is being promototed as a storage/smoothing/backup device for domestic solar installs and critical systems.
IE :- an alternative to the Powerwall , or the LG, Samsung, BYD, etc..home battery units.
Its claimed key advantages being its ultra long cycle life and operational life, together with its fire safety.

Running some LTO Titanate anode NCM cathode cells could deliver all of that as promised and perhaps it's not technically lying on its spec sheets about anything if they worded it carefully.

 

[Hillhater]

Running some LTO Titanate anode NCM cathode cells could deliver all of that as promised and perhaps it's not technically lying on its spec sheets about anything if they worded it carefully.

Sure but, Unfortunately they are promoting it as a "Supercapacitor" storage device...
.....which seems to be a false description !

The closest i can find to a spec sheet..
https://solarbatteriesonline.com.au/wp-content/uploads/2018/03/Super-capacitor-brochure-7.1-3.55.pdf

 

[Punx0r]

It's still not technically incorrect to call every lithium ion battery a double layer supercap that is recharged by an electro-chemical energy storage intrensic component.

Is this effect why the AC and DC discharge performance (and IR) of the cell differ so much?

 

[liveforphysics]

It's still not technically incorrect to call every lithium ion battery a double layer supercap that is recharged by an electro-chemical energy storage intrensic component.

Is this effect why the AC and DC discharge performance (and IR) of the cell differ so much?

Yep. ACIR only offers the capacitance, DCIR gives you how the cell performs in sustained loads (like an EV).

The advantage of ACIR is the ability to take a reading in a split second at each needed mfg step. The actual value in itself doesn't matter, but seeing that they are consistent gives a useful and quick QC rejection bounds (because it means electrolyte didn't wet all the layers perfectly or the coatings aren't the surface area and porosity level intended).

 

[Hillhater]

The KiloWatt Sirus battery pack may well perform as claimed, fast charge, 100k charge cycles, etc etc, ....
...however their own test results have provided the data which the guys on the AEVA forum have shown confirms that the device's are LTO cells, and not Supercapacitors
http://forums.aeva.asn.au/viewtopic.php?f=17&t=5486&sid=c448ae2226f151c952a37fde04576453&start=175
The Australian agents, ARVIO, is still doing tech presentations insisting these are Supercaps and are now digging a deeper hole by offering what they claim to be "supercap" AA replacement batteries (with built in USB charging).
Sadly ( and rather easily) these have also been shown to be relabled chinese LTO devices (available via Alexpress)
Why they have resorted to this cheap "market stall" type sales deception is beyond me, as they appear to have some very clever and practical products for Solar installs.

 

[liveforphysics]

Not questioning its LTO, but thst doesn't mean its a bad product or isn't a good part for the application.

I haven't safety tested many varieties of supercap, but what I have tested made LTO cell safety tests look like kittens in comparison.

Its not a bad thing at all to be using LTO for bulk energy storage, and not technically incorrect to describe them as an ion recharged super capacitor.

Perhaps poor marketing choices to stick to saying they aren't LIBs though. If someone has one if their cells handy you could prick for electrolyte, a LIB leaves a salt residude behind if you evap off its electrolyte with heating and super caps fluid should all eventually evap leaving minimal residue and no salt crystals.

 

[jonescg]

Yeah nobody has doubted the energy storage figures, and even the cycle life is good (really, 15,000 cycles would be enough) but to call it a supercapacitor instead of a lithium titanate cell is simply marketing.

 

[fechter]

Here is a datasheet from Maxwell for a new product they call a "Pseudocapacitor"
https://www.mouser.com/ds/2/257/CE_2017_Datasheet_2_3V50F_Pseudo_3001969_EN_1-1274211.pdf

These may be what they are using.