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Five times the energy density is quite a claim, especially given Samsung's announcement of batteries using "Graphene balls" only last November says only a 45% increase in energy density, albeit a 5x increase in charge rate. (I'm assuming it solves the problem of lithium metal deposition at high charge rates and possibly lower temperatures too)

Graphene Balls Reduce a One Hour Battery Recharge to 12 Minutes
 

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*
* up to 5 times :)
Well the article you linked does specifically claim "Graphene batteries have five times the energy density of the best Li-Ion battery."

I was just observing that this seems out of step with Samsung's claims of just a few months ago. But I'm not a battery expert by any means.
 

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Five times the energy density is quite a claim, especially given Samsung's announcement of batteries using "Graphene balls" only last November says only a 45% increase in energy density, albeit a 5x increase in charge rate. (I'm assuming it solves the problem of lithium metal deposition at high charge rates and possibly lower temperatures too)

Graphene Balls Reduce a One Hour Battery Recharge to 12 Minutes
At least for me that pcworld web page is unreadable. Here's the source article: Graphene balls for lithium rechargeable batteries with fast charging and high volumetric energy densities

Note that they aren't claiming a graphene battery, they're claiming that coating the electrodes of a lithium-ion battery with graphene balls improves charge rates.
 

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The indiegogo page for the actual product claims 5x faster charge rates, but doesn't seem to talk about energy density. Then again, it's quite detail shy and has some stuff embarrassingly wrong (like their timescale goes on about kickstarter, while being on a competing platform!).
The link from Duncan (to the actual experimental paper) points out that using this tech will result in 78% capacity drop over 500 charge cycles - that might be OK for a cellphone, but I'm not sure it's all that good for a car...
 

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Only if there's a massive rollout of 250kW rapid chargers. If the only chargers available go up to 50kW then your existing car will charge just as fast as the new improved ones.
Porsche are already on about 350kW and I can't see it being too many years before 100kW is a base level.
Even if it was stuck at 50kW the idea of having a far larger capacity in a smaller package would go a long way toward usability on it's own.
I can't see where it says 5x capacity but presuming that's even close to correct it would put most current bevs on 500-750mi ranges for similar battery sizes.
If that was the case the oil companies will need to scramble to cover their forecourts in the best rapids they can get because ice would be on the way out faster than a celebrity scandal.
 

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It looks like a win, win. Faster charging due to better handling of higher temperatures, and less degradation over time.
Some increase in energy density (27% claimed) would mean that for the same volume as a current(current get it...) 30kWh battery you would get 37kWh. The 5 time faster charging would potentially mean the time to 93% from empty of around 45-50 mins would realistically come down to 15-20 mins (assuming you can get the juice...).

Bodes well for future models. If only someone would take on the possibility of retrofitting new battery technologies into existing battery pack modules. That would really add value to the potential graveyard of 5 plus year old EV's that are absolutely OK apart from the reduced/unacceptable range. Fit those new cells, upgrade the BMS and Bob's your uncle. Say 8,000 to effectively get a car to perform as well as low end future models...
 

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Discussion Starter #13
I think the graphene technologies should show less degradation than Li-ion.
The 5 times energy density figure seems to come from the press release from graphenano, a Spanish company that claim an energy density of 1000 Wh/kg for their batteries.
 

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The link from Duncan (to the actual experimental paper) points out that using this tech will result in 78% capacity drop over 500 charge cycles - that might be OK for a cellphone, but I'm not sure it's all that good for a car...
At 5C and 60c though, really hammering the cells doing that, a car wont push them anywhere near that hard.

I dont have the figures, but i would imagine existing car cells would fare no better in those circumstances. Car cells are life managed by limiting max charge and discharge rates as well as carefully managing temperature and capacity.
 

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it makes leasing seem more desirable. It will certainly solve any range issues.
Indeed - having done the "Hurrumph. I don't take HP!" bit on my first Leaf, I quickly saw the benefits of PCP for my second and I can feel a PCH coming on for the next one.

OK, OK, some of us are slow learners.
 

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Graphene batteries have been available for the last 2 years at least,

Turnigy Graphene
Except they are Lithium Polymer batteries with some Graphene added for marketing purposes.

Five times the energy density is quite a claim, especially given Samsung's announcement of batteries using "Graphene balls" only last November says only a 45% increase in energy density, albeit a 5x increase in charge rate. (I'm assuming it solves the problem of lithium metal deposition at high charge rates and possibly lower temperatures too)

Graphene Balls Reduce a One Hour Battery Recharge to 12 Minutes
I hate, hate the abuse of the word Graphene and this is a typical example. Graphene balls don't exist. If it's a ball it's the exact opposite of what Graphene is. These are Buckyballs and along with Graphene Tubes (nanotubes!) have been commercially available much longer than Graphene has.
 

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Compared to a pure ICE, an EV is probably a better investment at this stage...
Longer term possibly but unlikely. Over a normal ownership term I can't think of any ev which genuinely loses less than it's ice equivalent. I really can't see that changing if big battery developments continue to be announced all the time or if the charge network and range don't improve dramatically.
Either one kind of cancels out the other so it's a bit of a no-win situation until the tech has matured and settled down.
 

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Longer term possibly but unlikely. Over a normal ownership term I can't think of any ev which genuinely loses less than it's ice equivalent. I really can't see that changing if big battery developments continue to be announced all the time or if the charge network and range don't improve dramatically.
Either one kind of cancels out the other so it's a bit of a no-win situation until the tech has matured and settled down.
First generation EV's that do under about 100 miles will depreciate heavily for two reasons.

1) If the battery degrades significantly the already short range becomes unusable for many/most people, whereas an EV that could do 200 miles when new with the same percentage battery degradation is still a perfectly usable car for most peoples needs.

2) When the battery breakthroughs do eventually come and 200+ mile range becomes the norm, early cars with 60-100 mile ranges will be obsolete, certainly as an only car - nobody will want them, except maybe as a cheap local runabout as a second car.

That's the price of being an early adopter with a short range EV though - and I think we're all aware of the risk.

I don't see any reason why high depreciation will continue indefinitely with EV's though. Once we get past this initial hurdle of short range EV's and a looming battery breakthrough and all EV's have a reasonably long range and/or little range degradation with use, and EV's have had a chance to prove themselves, depreciation will drop back to normal levels and quite possibly less than an ICE.

In fact when the majority of vehicles are EV's why would depreciation be high, if that's all you can buy ?
 
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