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When ICE cars & lorries etc became mainstream transport, horses became rather a side-line. There continues to be a type of person that seeks to optimise these equine engines, but it's very much a minority past-time! :)
 

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Likewise in the UK most of the year.
Looks like a failure to do the math, again. Or magical thinking.

A REx isn't on most of the time. Fraction of time on t1.

The heat output isn't useable at all for a fraction of the time t2.

Only part of the heat output is needed, fraction h1.

REx adds mass, other losses.

40% efficient REx, + 40% heat * t1 * t2 * h1 - losses.

Somehow, I don't see the case for better than a 70% combined cycle gas plant efficiency.
 

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?

Facinating.

Can you do a quick sketch of the connections between this heat pump and a car moving at 70mph?
Two words.

Cold outside.
 

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Seems a bit 'dishonest' to sing loudly about the golden age of BEVs to come by discussing future battery tech, while critiquing heat engines only with reference to current ICE technology. What if we reversed that paradigm; we can only discuss today's battery technology when looking at future radical heat engine developments? That wouldn't seem fair, right?
Horses had a problem. Piles of poo.

Sorry, but I'm not into shoveling. And that's not one bit dishonest.

Tesla isn't using L(MO)x-C for their latest batteries. So find another limit.
 

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Discussion Starter · #26 ·
Looks like a failure to do the math, again. Or magical thinking.
No, this is a failure in the English class for you again, just go look at what I said originally, and see if you understand the meaning of the word 'can' in a sentence.
 

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Discussion Starter · #27 ·
Tesla isn't using L(MO)x-C for their latest batteries. So find another limit.
Tell me more, I am interested to know.

What cars can you buy from them with something different in?
 

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It seems beholden on me, as (it seems) the only professional engineer here with this sort of background, to explain why lithium ion batteries, in their current technology, are limited and not going to go much further.
The fundamental energy density limitation with current Lithium Ion batteries which you're talking about is the graphite electrode which has to "store" the mobile Lithium Ion's. It just doesn't allow very dense storage of Lithium Ions, and it's this end of the cell that's really the limiting factor. As you say, we're not far off reaching maximum theoretical energy density for a graphite electrode cell. Silicon is better at storing Lithium Ions more densely but swells and shrinks too much as Ions pass in and out causing fatigue failure very quickly.

A Lithium metal electrode in place of graphite offers a seriously higher theoretical energy density (something like 5x to 10x ? It's a while since I read up on it) however there are many, many problems with Lithium metal electrodes that are keeping them in the realm of laboratory experiments. One being dendrite growth that would occur on a Lithium metal electrode with a liquid electrolyte as you couldn't get the ions to deposit in metallic form in a uniform way on the electrode without growing whiskers through the electrolyte and eventually shorting the cell out.

From what I understand, one of the potential benefits of a solid electrolyte (aside from being less flammable/dangerous etc) is that you could use electrodes such as Lithium metal that would otherwise be infeasible in a liquid electrolyte due to dendrite growth. If you have a solid electrolyte that Lithium Ion's can pass through but Lithium metal cannot, dendrites can't form and the resulting catastrophic shorts can't happen.

So maybe the next big energy density breakthrough is a Lithium metal electrode together with a solid state electrolyte ?
 

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A
No, this is a failure in the English class for you again, just go look at what I said originally, and see if you understand the meaning of the word 'can' in a sentence.
Ah so you were in sales. Imply that once every couple of years it might be cold enough for a few minutes to do as you say.

I was in engineering, so sorry I used math rather than misleading words.
 

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So the cells of a 500kWh BEV's battery alone would weight at least 1,500kg. Not practical.
Don't see why not. If we consider a Hummer is 'practical'. It would be an outlier for sure, at least until HGV EVs become commonplace, but some people like that kind of thing.

I recently visited the British Motor Museum in Warwickshire. There are a huge variety of different sized (and 'weighted', if that's a word) cars there, some light, some heavy. I highly recommend it. And 1 500 kg is actually lighter than my Leaf, albeit there is a bit more to it than a battery.
 

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Tell me more, I am interested to know.

What cars can you buy from them with something different in?
Model S Plaid. Same size cells, more energy. Replace (some?) of the C with Si.
 

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Discussion Starter · #32 ·
Model S Plaid. Same size cells, more energy. Replace (some?) of the C with Si.
Is that a question?

I have no idea. I wish them well with it, if they have, and what's your point?
 

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Discussion Starter · #33 ·
A Lithium metal electrode in place of graphite offers a seriously higher theoretical energy density (something like 5x to 10x ?
I think you are confusing lithium-air batteries.

If you remove the carbon completely and somehow, through sheer pixie magic, hold the lithium ions floating around 'somehow', then you still have the L(MO)x electrode to deal with, as the source of the lithium ions, each ion being coupled with a molecule of mass density 186g/mol (rather than 260g/mol if you include the carbon electrode).

That increases your L(MO)x type battery by 260/186, or from ~300Wh/kg to a maximum of ~420Wh/kg.

That is very nice, thanks, but not exactly 'game changing'. Not really 'a different technology'.

You have to change the L(MO)x electrode to go anywhere more than that. Get rid of the lithium mineral electrode altogether as the source of lithium ions, and just have metal. There are an assortment of problems there, safe stability being one, but it is difficult to reform ions back into their elemental form directly without a binding molecule containing a transition element. If you get rid of that, then of course you can go from 260g/mol to 78g/mol, being nearly 4 times more dense.
 

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Might be worth a read...


One other observation I'd make is that we actually only need about a factor of 2 improvement in energy density over what we already have in the best EV's today to reach a point where battery weight for an acceptable range is sufficiently low that a 250 mile range EV can reach weight parity with an ICE vehicle, and any improvements beyond that are just gravy.

It's not like we need an order of magnitude improvement to make EV's work.
 

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Discussion Starter · #35 ·
It's not like we need an order of magnitude improvement to make EV's work.
Yes and no. The problem here is that everyone is merely thinking about the longest trip they might make. This represents about 100% of current users but about 10% of future users. The 90% remaining, in the absence of a personally owned charge point, need a big battery as they can only get to charge once a fortnight.

That is what REx could help solve today.

No matter how large the capacity of the battery, it still HAS to consume a certain amount of limited materials. Make batteries double the capacity, you can only make a half as many.
 

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Yes and no. The problem here is that everyone is merely thinking about the longest trip they might make. This represents about 100% of current users but about 10% of future users. The 90% remaining, in the absence of a personally owned charge point, need a big battery as they can only get to charge once a fortnight.
As about 60% of all UK drivers can provision charging at home, the above makes no sense at all.

Must of been written by someone in Marketing, rather than Engineering.

Batteries can be recycled. Fuel is consumed.
 

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Yes and no. The problem here is that everyone is merely thinking about the longest trip they might make. This represents about 100% of current users but about 10% of future users. The 90% remaining, in the absence of a personally owned charge point, need a big battery as they can only get to charge once a fortnight.

That is what REx could help solve today.
I think your assumptions are inaccurate, estimates suggest somewhere around 70% of households have or could have off-road parking with EV charging, so that's somewhere around 70% of EV users who would be fine with the existing technology. I know you like evidence so I've included a link:

RAC Foundation - Car usage and parking report

Of the remaining 30% with no home charging, is there any evidence for this assumption that they can only charge once per fortnight? Where has this assumption come from? As the roll out of charging facilities progresses I would expect most drivers would have lots more opportunity than this, with chargers being rolled out at public car parks, workplaces, destinations, on-street and rapid chargers.

That's not to say it isn't a problem at all, there will be users without home charging with limited access to public charging, but I'd think the number limited to access once a fortnight is likely to be in the low tens of percent, if that. After all if they are using their EV, it's to drive to destinations and as the infrastructure rolls out, that will mean driving past charging facilities or to destinations with charging facilities.
 

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Discussion Starter · #38 ·
As about 60% of all UK drivers can provision charging at home, the above makes no sense at all.

Must of been written by someone in Marketing, rather than Engineering.

Batteries can be recycled. Fuel is consumed.
No, the survey is done and it is about 1.5 million out of 22 million households, about 5%.

Please show me your data. I have shown you mine.
 

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No, the survey is done and it is about 1.5 million out of 22 million households, about 5%.

Please show me your data. I have shown you mine.




No Driveway? You Can Still Have an Electric Car | Pod Point (also reference the PWC report)

A third of UK homeowners don’t have a driveway or garage to (also talks about distribution, with rural areas - where public / on-street charging is scarcer - having much greater scope for off-street charging, than city centres)

Not that @WetEV needs my help and despite the fact that arguing with some people is like trying to paint fog :).
 

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Discussion Starter · #40 ·




No Driveway? You Can Still Have an Electric Car | Pod Point (also reference the PWC report)

A third of UK homeowners don’t have a driveway or garage to (also talks about distribution, with rural areas - where public / on-street charging is scarcer - having much greater scope for off-street charging, than city centres)

Not that @WetEV needs my help and despite the fact that arguing with some people is like trying to paint fog :).
"Access to off-street parking" doesn't sound like "suitable for home charge point installation" to me. Clearly the latter is a considerably smaller subset of the former.

Home charge points under the current scheme require the property where the charge point is to be installed to be occupied by the application.

What, exactly, is the relationship between 'access to off street parking' and the condition 'resident in the property'?

WetEV said:
As about 60% of all UK drivers can provision charging at home,

When he actually meant 'maybe a charge point can be put in somewhere near to their home' because for sure many, possibly most, of that 'off street' parking provision is not 'home'.

We have seen dozens of examples here on the forum where if a person's parking space is not right next to their house, on contiguous land, they are usually denied charge point funding, even if they can get around all the technical hurdles.

This is A LOT BIGGER than simply 'having off-street parking'. It's about whether they have ownership of that parking, whether they have exclusive use, whether electricity can be hooked up, etc..

Another recent survey said only 1.7 million homes were suitable to have charge points fitted.

If you want to include all the possible 'off-road parking locations' then tell me how that is going to be achieved in the cases where no-one has ownership of those locations? That is a far far cry from WetEVs 'can charge at home' when it was actually 'somewhere near, maybe, if land ownership and electricity supply can be sorted'.

And in the cases for the remaining 12 million cars that have no 'off-road' provision, they can go swivel, because you say so, right?
 
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