# MIT LiPo4 Battery breakthrough promises 100-fold boost in performance



## Jason Lattimer (Dec 27, 2008)

Tell me what you think of this article. Looks promising.
http://www.gizmag.com/lithium-ion-battery-breakthrough-mit/11244/


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## PhantomPholly (Aug 20, 2008)

Wonder if this is a real breakthrough or if it will run into the tradeoff that other similar approaches have had where the total number of charge cycles are exchanged for more rapid charging. Hopefully it pans out.


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## Jason Lattimer (Dec 27, 2008)

I kind of thought the same, because I figure a solid plate is more durable than a plate with lots of little holes in it. Hopefully I am wrong though.


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## PhantomPholly (Aug 20, 2008)

Jason Lattimer said:


> I kind of thought the same, because I figure a solid plate is more durable than a plate with lots of little holes in it. Hopefully I am wrong though.


Maybe they'll develop little tiny hole cleaners?


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## david85 (Nov 12, 2007)

Well first of all, 50 cycles is nothing in terms of what a conventional LiFePO4 battery can deliver. Most actually gain some capacity over that number of cycles.

Second, the battery is only part of the problem when it comes to how quickly it can be charged. You still need a power supply that can support that many amps (along with buss bars and the rest of the car's internal traction wiring).

My car takes about 8 hours to charge not because of the batteries, but because any faster and the breaker gets thrown.


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## Jason Lattimer (Dec 27, 2008)

david85 said:


> Well first of all, 50 cycles is nothing in terms of what a conventional LiFePO4 battery can deliver. Most actually gain some capacity over that number of cycles.
> 
> Second, the battery is only part of the problem when it comes to how quickly it can be charged. You still need a power supply that can support that many amps (along with buss bars and the rest of the car's internal traction wiring).
> 
> My car takes about 8 hours to charge not because of the batteries, but because any faster and the breaker gets thrown.


I believe it said they have only tested it to 50 cycles, so lets hope it stands up to several thousand cycles. If it works, you could have super quick charge stations at your local gas stations and still plug in over night.


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## PhantomPholly (Aug 20, 2008)

Jason Lattimer said:


> I believe it said they have only tested it to 50 cycles, so lets hope it stands up to several thousand cycles. If it works, you could have super quick charge stations at your local gas stations and still plug in over night.


Exactly - if the super-quick charge stations also have quick-charging / quick-discharging batteries to manage the "instantaneous demand," and enormous hookup cables. I think some of the smarter guys on this forum did a post a while back suggesting that the cables would need to be enormous to give a 200 mile charge in under 10 minutes, but I suppose it also depends on things like voltage and resistance to heating.


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## david85 (Nov 12, 2007)

PhantomPholly said:


> I think some of the smarter guys on this forum did a post a while back suggesting that the cables would need to be enormous to give a 200 mile charge in under 10 minutes, but I suppose it also depends on things like voltage and resistance to heating.


Wasn't me, but I remember that being said.


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## Jason Lattimer (Dec 27, 2008)

The only other problem I see is this. Has anyone ever seen a charger for a DC quick charge? Does one even exist?


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## JRP3 (Mar 7, 2008)

Sure, remember the LEAF comes with the CHADEMO DC quick charge port, and Aerovironment has done under 10 minute recharges of Altairnano batteries. As pointed out, the real limit is the power supply, not the battery at this point.


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## PhantomPholly (Aug 20, 2008)

A "charger" could be something as simple as another (presumably larger) bank of batteries that runs at a slightly higher voltage than the target pack. Hook up the cables, then activate the "Mother of all Contactors" for a quick charge.

Kind of like filling an O2 bottle from a bigger bottle...

I'm actually thinking about a setup like this for our next house (within the next year). When we move in, I want to include a solar array in the purchase price, possibly including a bank of backup batteries for full off-grid operation. If I can make us 100% off-grid, and if the additional investment only raises the mortgage payment by the amount of my estimated utilities today, then I'm money ahead in the long run (as energy prices rise and my mortgage stays the same). At 4% interest on a 20 year loan, adding (for example) $60,000 to your mortgage increases your monthly payment by about $360. Not counting any subsidies / tax credits at all, that's enough to fund a 20Kw grid tie system (parts only, DIY). That's about 4,000 Kw/Hrs/Month of energy (Atlanta area, averaged over a year), more than even most well-sized homes use and already less per month than I'm paying for utilities averaged over a year.


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## JRP3 (Mar 7, 2008)

Yes dump pack fast charging is possible, I think some people have played with the idea. However a pack capable of providing that type of power repeatedly will be expensive.


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## PhantomPholly (Aug 20, 2008)

JRP3 said:


> Yes dump pack fast charging is possible, I think some people have played with the idea. However a pack capable of providing that type of power repeatedly will be expensive.


Absolutely - which is why I don't think "filling stations" will go away any time soon.

Think about it - a service station has several hundred cars each day "fill up." Even with 440v service and a gi-normous service cable, it would be difficult or impossible to keep up with peak demand. However, replace one underground gas tank with a monster battery (or capacitor) pack and you can smooth the demand over day/night. Such a pack will pay for itself in very little time.


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