On December 2 at EVS23, A123Systems publicly unveiled the lithium ion battery cell that they have co-developed with GM specifically for the Volt. It is a flat “prismatic” cell that is significantly larger than the cylindrical cells that we are used to seeing from A123. The cell is rectangular, and is designed to be stacked within the pack like slices of bread. GM chose a stackable, space-efficient battery format for the Volt so as to minimize the volume of the pack.
Exact specifications of the cell have not been released.
According to A123 engineers at the event, they have also developed proprietary algorithms that can precisely monitor their battery technology’s voltage and state of charge – thus eliminating concerns that the battery could suddenly drain completely empty without warning. They developed this software as a part of their hybrid electric bus program, which is independent of their collaboration with GM.
GM’s Denise Gray has stated in the past that they are developing their own battery management software “in-house”, so it is unclear if A123’s software will be shared as a part of the Volt program.
[Thanks to AES for this guest post! - LD]
This entry was posted on Monday, December 3rd, 2007 at 7:33 am and is filed under Battery, E-Flex, E-REV. You can follow any responses to this entry through the RSS 2.0 feed. Both comments and pings are currently closed.
Dec 3rd, 2007 (8:11 am)AES
Thanks, this is great news. It is pretty exciting hearing about the progress unfolding, although is kind of torturous not knowing the specs.
Dec 3rd, 2007 (8:19 am)I would assume this pack was delivered to GM prior to the public unveiling? Anyone know if GM has one in their hot little hands?
Dec 3rd, 2007 (8:43 am)Thanks AES and Lyle, I have been on pins and needles waiting to hear about the A123 Prismatic Cell.
I do not think GM has the battery pack yet, but I expect more than 120 cells have been shipped to Continental AG for packaging into a battery for shipment back to GM by the end of the year for bench testing.
It is hard to estimate the module size shown, but a 10″ by 10″ module that holds 15 cells seems in the ball park. So a row of six capped by a cross row of three in the shape of a “T” would drop right into the 3 foot by 6 foot “T” space for the battery of the Volt.
Now we wait for news that Continental AG has shipped the assembled battery to GM’s lab. Go Volt!
Dec 3rd, 2007 (9:14 am)I am impressed! Thanks Lyle and everyone.
Dec 3rd, 2007 (11:38 am)Thanks for the positive feedback everyone.
From what I understand, GM provided A123 with lab space and test equipment to develop this new cell in a very short period of time. LGChem/CPI already had their cells designed, so I suspect that’s why they delivered their pack before Continental.
So now we are just waiting on ze Germans to come through…
Dec 3rd, 2007 (12:37 pm)This is very good news. Nice find AES.
Dec 3rd, 2007 (1:42 pm)The gods have smiled!
Dec 3rd, 2007 (2:01 pm)nice!
Dec 3rd, 2007 (2:10 pm)Allah has blessed A123systems.
Dec 3rd, 2007 (4:44 pm)Now we are getting somewhere!!!!
After initial testing, is the next step to get some “mules” on the road?
Dec 3rd, 2007 (4:57 pm)Let’s “pack” those mules and get some work done.
Good job A123.
Dec 3rd, 2007 (7:13 pm)I thought that I had been paying attention, but I guess I missed something. How does Continental AG fit into this?
Are they just involved in the prototype stage, or are they goiing to replace the Chinese outfit that evidently bailed?
Dec 3rd, 2007 (7:18 pm)[quote comment="17622"]I thought that I had been paying attention, but I guess I missed something. How does Continental AG fit into this?
Are they just involved in the prototype stage, or are they goiing to replace the Chinese outfit that evidently bailed?[/quote]
Noel-
Continental is going to take the cells that A123 makes, and build them into modules and packs that meet GM’s automotive-grade specifications.
CBAK (sp?), the Chinese company you referred to, was just a manufacturing partner. I don’t know for sure, but I think A123 was basically just renting space in their factories until they got more money to build their own facilities.
Dec 3rd, 2007 (7:19 pm)Wow!
GM-Volt.com – the voice of authority!
Dec 3rd, 2007 (8:00 pm)it would be nice to know more about the battery specs.
Dec 3rd, 2007 (8:30 pm)More than just renting space. They were A123’s manufacturing sub. Much of what A123 has made has actually been made by CBAK to A123’s specs.
Meanwhile the competition heats up! Ford is not sitting still and is working with JCI-Saft. They’ve been unveiling also. No Volt this one, a smaller battery and a smaller range and it is unclear how much is really all electric but still …
“The research prototype uses a 10 kWh lithium-ion battery pack from Johnson Controls-Saft based off a 41Ah cylindrical cell. Ford and JCS developed the plug-in pack together. The PHEV uses a blended operating strategy, and delivers an equivalent 30-mile all-electric range, according to Ford.
The pack runs in charge-depletion mode down to approximately a 30% state of charge, before switching over to charge-sustaining mode.”
Dec 3rd, 2007 (8:38 pm)Yep, I saw the plug-in Ford at EVS as well. The domestic automakers seem to be universally much more bullish about lithium than Toyota.
JCI-Saft has very good technology. Pity they didn’t make it into the Volt pipeline.
Dec 3rd, 2007 (8:44 pm)Did A123 part company with China Battery for the Volt battery and build a factory of their own in China?
Or do they have a new manufacturing sub contractor.
Ive seen them associated with Prius conversions through Hymotion.
This spelling checker is good. Thanks all for the recommendation of Firefox
Dec 3rd, 2007 (9:36 pm)[...] [...]
Dec 3rd, 2007 (10:11 pm)CBAK and A123 did not renew their relationship. Allegedly this came from CBAK and allegedly over exposure to potential patent lawsuits still in play. There is no word on a different sub. They do have funding to build more of their own factories (they have some already) but getting to enough capacity in time seems like a tall order.
AES, could you please revisit the first thread on CAFE standards and help me out there? I’d really like to understand how the Volt will be rated for mpg under CAFE as proposed by Argonne and I am not sure that I understand it correctly.
And thanks for this thread!
Dec 3rd, 2007 (10:26 pm)Thanks Don,
That was my nagging doubt, can they produce 60,000 units in 2011.
By then the gm-volt waiting list may be 30,000 so thats a half of the production spoken for already.
Dec 3rd, 2007 (11:10 pm)Don-
Not sure if I can help much(yet) but I responded anyway with some interesting stuff I found on Argonne’s site.
If anyone’s interested to know, when I talked to the A123 staff at EVS, they had a HUGE, fully-operational battery pack for a hybrid bus put together. Very impressive, esp since it was made using their small power tool cells.
Even more impressive since with HEVs, you have to keep the battery pack within a very narrow range of charge, since shallow charging maximizes life, and optimum power is found in a narrow range as well.
So, in order to do that, you have to be able to measure the state of charge with extreme accuracy – in other words, measure extremely minute changes in voltage. That’s a much more difficult task than that encountered by a PHEV like the Volt, since you’re going all the way up and down the charge range, and measuring much larger changes in voltage.
Doug Korthoff has made a big deal about A123’s cells having a flat discharge curve, but apparently, and I quote A123: “it’s not as flat as you think”.
Anyways, either we buy into A123’s hype or we don’t, but it’s fascinating nonetheless that they went after the most technically difficult task (HEVs) first. So even if the Volt gets cancelled (unlikely at this point), we could still look to a BAE systems hybrid bus as evidence that the lithium ion technology really is ready:
http://www.baesystems.com/Newsroom/NewsReleases/autoGen_10747202843.html
Dec 4th, 2007 (12:26 am)That seems to be a far cry from the flat long “T” shaped cell that the Volt was designed for.
Beyond that we obviously know nothing. Hmmmmmm?
M.
Dec 4th, 2007 (2:35 am)mykallb-
The t shape describes the pack, not the cells that it is composed of.
Dec 4th, 2007 (11:53 am)bruceg, #21:
gm-volt waiting list 30,000 – damn right – we look to the day!
Dec 4th, 2007 (12:25 pm)The waiting list can be 1 million, as long as we here at GM-VOLT.com are at the top of the list!!!!!
Dec 4th, 2007 (5:49 pm)[...] [...]
Dec 4th, 2007 (5:49 pm)[...] [...]
Dec 4th, 2007 (11:59 pm)# AES Says:
December 4th, 2007 at 2:35 am Quote
mykallb-
The t shape describes the pack, not the cells that it is composed of.
=====
None the less, it must conform to spec. Roughly speaking you’re going to need approx. 400lbs of batt. You develop a vehicle to accommodate that which will be. Uhhhh the “big square” pack is not going to fit the Volt specifications as I understand them.
So…if you’re testing cells, then you’ve got a point, but if you’re testing a viable batt. then we’ve got some concerns.
M.
Dec 5th, 2007 (7:42 am)mykallb #29:
I am a bit confused with your posts. Nowhere in the original article are any size or weight figures given for the pack that is shown. This quote is from the original article: “Exact specifications of the cell have not been released.” And as I understand it, the final design of the actual vehicle is far from being at the “design freeze” stage.
So how is it that you have come up with a weight of the full pack, and been able to determine that the size of the pack will not fit into the Volt?
Unless you have access to information that does not seem to be available, or have actually held this new pack in your hands, I think your conclusions are a bit premature.
IMHO, if the packs from A123 or LG did not come close to meeting the GM defined specs, I doubt seriously that they would be issuing press releases about the delivery of them to GM.
Dec 5th, 2007 (8:57 pm)Jim I Says:
December 5th, 2007 at 7:42 am Quote
I am a bit confused with your posts. Nowhere in the original article are any size or weight figures given for the pack that is shown. This quote is from the original article: “Exact specifications of the cell have not been released.” And as I understand it, the final design of the actual vehicle is far from being at the “design freeze” stage.
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Jim,
Where do you get this information? On this very site Frank Weber stated just the opposite. He stated roughly that the Volt was near the design freeze stage. That’s a far cry from your “understanding”.
Dec 6th, 2007 (9:52 am)Lets assume the energy density of the new prismatic cell is 125 wh/kg. This is based on the assertion that the new cell has an energy density about 20% higher than the round cell. (108 x 120 = 130) So the weight of the cells necessary for 16 KWH is about 130 Kg or 290 lbs. Naturally the battery cooling and managment equipment would add to the weight, but a battery pack of about 400 lbs seems feasible.
The “T” battery storage compartment shown on the concept vehicle drawings runs from the back of the engine compartment to the rear where it “t’s” near the real axle.
Dec 6th, 2007 (10:45 am)mykallb
“Uhhhh the “big square” pack is not going to fit the Volt specifications as I understand them.”
Where is the “big square” pack mentioned?
May 3rd, 2008 (11:27 pm)I wish they would sell the 40 mile range battery pack so I wouldn’t have to buy a $35,000 volt. I don’t want much more range than 40 miles. My lead Acid converison that will have a range of 45 miles is costing $3000