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View Full Version : 400 wh/kg is here ?



Hugues
27 February 2012, 0957
Any opinion on this company ?

http://enviasystems.com/announcement/

claiming 400 wh/kg, tested independently,

today's press release:
http://enviasystems.com/pdf/Press_Release_400WHK.pdf

teddillard
27 February 2012, 1033
The whole thing feels very understated. Also, there seems to be some pretty good independent testing and actual delivered product.

Imagine that! :rolleyes:

Looks awesome to me!

Nuts & Volts
27 February 2012, 1057
Definitely does not seem like vaporware with actual costs, but I will bet it won't be manufacturer-able or cheap enough for consumer cars for another 5 years or so.

Prove me wrong GM! haha

ZoomSmith
27 February 2012, 1110
That's all great press-release material, but I don't see a distribution channel listed.
How are you going to obtain these "super-awesome" cells?

larryrose11
27 February 2012, 1222
In the introduction area, they say they only did 23 cycles, but the chart list 300 cycles. The chart also shows an intal steep drop in capacity, (about 23 cycles?) and then flattens out. No mention of this 300 cycle test, or did I mis somthing?

Kane
27 February 2012, 1253
No mention of this 300 cycle test, or did I mis somthing?
"Similar cells have been cycling in Envia’s test labs for over 300 cycles."

Anyway, this cells have low power density.

Hugues
27 February 2012, 1301
Anyway, this cells have low power density.

??
you mean you don't believe they have 400 wh/kg
or
you say 400 wh/kg is low power density ?

from this chart, 400 wh/kg is double of the best cells available:
http://mabula.tangram.dnsalias.net/battcomp/cell_stats?s=whkg

Skeezmour
27 February 2012, 1321
??
you mean you don't believe they have 400 wh/kg
or
you say 400 wh/kg is low power density ?

from this chart, 400 wh/kg is double of the best cells available:
http://mabula.tangram.dnsalias.net/battcomp/cell_stats?s=whkg

There is a difference between energy density (400wh/kg) and power density (400w/kg as an example). so if I had a 4kwh pack it would only be good for 4kw output. There are cells that have amazing energy density but you have to pull it out very slowly. Then there are cells with AWESOME power density but not very high energy density. Trick is getting cells with the right balance for your application.

Hugues
27 February 2012, 1324
..and i stand corrected !
thanks

but what's their w/kg then ? so we can benchmark them against this chart
http://mabula.tangram.dnsalias.net/battcomp/cell_stats?s=whkg

liveforphysics
27 February 2012, 1411
This cell and the other dozen high voltage chemistry options all have the same problem, no solvent/electrolyte exists that doesn't rapidly decompose OR cost $10,000 per liter.



I edited my post. I would just like to say, I REALLY REALLY hope this is not something that involves unobtainium, unicorn horn powder, or doesn't have a mechanism to increase the C-rate and cycle life.

Because 16kw-hr's of energy storage for 40Kg of weight would make every motorcycle be an electric.

jazclrint
27 February 2012, 1530
What about 400wH/liter? http://www.youtube.com/watch?v=44EaTcV_-4o&feature=share

Where does that stack up? Non toxic, and so stable all you need is a very basic BMS. The problem is, as mentioned above, the discharge rate is pretty low. Is this where super capacitors could help?

[Edit] Sorry, try this link. http://www.eosenergystorage.com/documents/EOS-Website-Presentation_1-5-12.pdf

The other is an hour long webinar.

Richard230
27 February 2012, 1531
The report on the local radio financial news blurb (take that for what you will) says that production of the cells should start by 2014. I assume that is if they get enough investment money to build a factory and do all of the other stuff necessary to produce, market and distribute their batteries. What worries me is that the government gave them a grant - and you know what that means. :O

ZoomSmith
27 February 2012, 1628
if they get enough investment money

the government gave them a grant - and you know what that means

Oooboy. There's the kiss of death.

larryrose11
28 February 2012, 0555
Richard230, Zoomsmith,
Not to get off topic, Grants are the kis of death? Whaaa? Explain please? The Gov gives out grants all the time for all kindsa of stuff. Education, Research, to name just 2. Hell, the DarpaNet started out as a grant.

Back on topic:
So, this 45 Ah cell they showed off can discharge at 45 amps (1c) Thats all? So, the best way to use somthing like this is crazy high voltages. To get 30 kW out of a pack of 2 paralell cells, thats 90A limit, what would the voltage be?
30000W/90A=333.33 V (!!!)
I think they need more reaction area to get the C-rate up!!

ZoomSmith
28 February 2012, 0806
Larry,
Specifically, stimulus funds to "green" ventures.
Enerdel, is the most recent one that comes to mind.
The term "grants" was a little broad.
Back to our regularly scheduled thread.

Richard230
28 February 2012, 1045
Larry, that comment was meant to be a joke. It seems like every alternate energy company that has failed recently has received a "government grant" in the amount of millions of dollars.

Moving on.....

This story hit the business section of my newspaper today. In an article written by Dana Hull of Mercurynews.com, it is stated that “Envia (Systems) was awarded a $4 million grant from ARPA-E in December 2009 to develop advanced lithium-ion batteries for electric cars. It went on to raise $17 million in venture capital from General Motors Ventures, Bay Partners, Redpoint and Pangaea Ventures. In a separate agreement, GM secured the right to use Envia's technology for GM's future electrically driven vehicles.”

An interesting comment in the article was provided by Mike Omososo, a senior auto analyst with LMC Automotive, who said: “It does sound very impressive, but it remains to be seen if it will work outside the lab”. “Since most EV and plug-in makers have already got battery suppliers in place, it may be a few years before we see the Envia batteries in vehicles on the road”.

The article also mentions a statement by Envia that “When commercialized its 400 wh/kg battery, which will provide a range of 300 miles and cost about $25,000, will slash the price of electric vehicles, making them more affordable for mainstream customers”.

The article concludes with the following statements: “While there's been talk in the industry of moving beyond lithium and using new materials, many expect lithium-ion batteries to remain dominant in the coming decades.” “The rumors of the demise of lithium-ion batteries were greatly exaggerated.” (A quote by Evia's CEO Atul Kapadia.)

The article also mentions that there are "at least two dozen battery start-ups" in the Silicon Valley area. To me, that sounds like a risky business to be in, unless you are very well funded, have a lot of industry connections and are working on a "world beater" battery design.

liveforphysics
28 February 2012, 1059
Back on topic:
So, this 45 Ah cell they showed off can discharge at 45 amps (1c) Thats all? So, the best way to use somthing like this is crazy high voltages. To get 30 kW out of a pack of 2 paralell cells, thats 90A limit, what would the voltage be?
30000W/90A=333.33 V (!!!)

No matter how you arrange it, you only get 1-C discharge. Makes no difference on if you go high or low voltage, only the number of cells.

For example, if you have space/budget for 100 cells, you can arrange it 10s10p and have a ~32v pack with 450Ah that can discharge at 450amps @32v (14.4kw), or you could arrange it to be 100s1p, and it's 320v45Ah, and can discharge at 320v @45amps, which is also exactly 14.4kw.

High or low voltage, you can never get past C-rate limitations.




I think they need more reaction area to get the C-rate up!!


Whatever they did to keep the silicon anode structure from collapsing and breaking away from the current collector more thoroughly than the cycle life graph shows is going to extend beyond pumping reaction area.

larryrose11
28 February 2012, 1428
Shameless plug...

I was cold called the other day by a Dow-Kokam, asking If I knew anyone looking for employment. So, I thought I would just throw this out.
Anyone interested in a position as a battery engineer (Dow Kokam-Lead Systems Engineer)?
If So, PM me your email contact, and Ill fwd you the info.
Larry