Kia rejects Li-ion for Pb-carbon in hybrid car
electronicsweekly.com
electronicsweekly.com
Is this line actually true: "An often-overlooked feature of most Li-ion cells is that they cannot and must not be charged below 0°C, and have poor output current below 0°C."
Most consumer-grade lithium ion batteries have a charging window between 0-45C, totally unacceptable for a car. 0-60C is more common for automotive batteries, but still isn't that large of a window.
http://i.imgur.com/TOUXlWM.jpg
The car needs a substantial amount of both active heating and cooling in order to enable the batteries to both charge at all below 0C and to charge and discharge extremely rapidly when attached to a Supercharger or under heavy acceleration.
Every year when winter comes, there's a huge spike in starter battery sales. I'm not sure what you mean by "dis-proven".
Start here: http://www.evdl.org/
Car batteries are lead acid, not lead carbon. I'm not familiar with the technology, but I wouldn't assume the same performance for different chemistry.
And the most relevant paragraph: The performance of all battery chemistries drops drastically at low temperatures. At –20°C (–4°F) most nickel-, lead- and lithium-based batteries stop functioning. Although NiCd can go down to –40°C (-40°F), the permissible discharge is only 0.2C (5-hour rate). Specially built Li- ion brings the operating temperature down to –40°C, but only on discharge and at a reduced discharge. With lead acid we have the danger of the electrolyte freezing, which can crack the enclosure. Lead acid freezes more easily with a low charge when the specific gravity of the electrolyte is more like water.
I couldn't find any capacity / discharge curves though.
I read about it here: http://www.gizmag.com/dual-carbon-fast-charging-battery/3212...
With original source here: http://powerjapanplus.com/about/news.html
"PbC lead/carbon chemistry creates a much longer lifespan (3 to 4 times), much greater charge acceptance in partial state of charge applications (10 to 20 times more depending on the "state" of the battery)."
http://www.torquenews.com/119/axion-power-pbc-battery-techno...
A regular LAB has about has around 2000 cycles. A LAB with carbon additives is not much better. See slide 16:
https://dl.dropboxusercontent.com/u/26257506/ELBC%202012/4_h...
Thus, Axion's PbC could have 8k cycles of complete charge/discharge, and orders of magnitude greater for partial discharges (which is how it would actually be used).
I have read it's over 100k cycles but I need to find the source.
"Our test protocol requires a complete charge-discharge cycle every 7 hours to a 100% depth of discharge. During testing, our laboratory prototypes have withstood more than 2,500 cycles before failure. In comparison, most lead-acid batteries designed for deep discharge applications can only survive 400 to 600 cycles under these operating conditions."
The interesting part about their batteries isn't the lifespan, it's the lifespan under 100% depth of discharge. You can easily get around 2k cycles out of a flooded cell lead-acid battery, but you can only go down to 60% discharge and you must carefully monitor the battery chemistry to get prolonged lifespan. Along with it's high current capacity, this would make it an interesting battery for renewable energy storage more than anything else.
It's too bad they don't have a solid datasheet for their product yet. I'd like to see their figures for internal resistance, self discharge and performance over typical operating temperature ranges. Until we get to see this data, it's hard to say if this will be a profitable product.
The last section covers the PbC characteristics.
I would also read the ASME Conference paper, written by Norfolk Southern's engineers about their electric train utilizing the PbC.
What the PbC does is have a carbon electrode on the negative plate, which prevents most of the sulfation problems. The positive plate experiences much less.
This is exciting because hybrid vehicles and other power applications demand many more cycles than traditional ICE auto. Previously this niche was only available to expensive and explosive Li-ion batteries. Now cheaper and safer lead-carbon batteries could be used (though they contain less energy).
Axion Power is a development stage company that holds the patent for a pure negative electrode PbC. Other competitor batteries pale by an order of magnitude to the number of cycles it can take.
It currently has the train company Norfolk Southern developing an all-electric train using Axion's batteries.
http://cleantechnica.com/2013/10/26/new-life-green-weenie-el...
Axion also has auto companies, energy storage companies, and trucking companies developing apps using the PbC.
http://www.marketwatch.com/story/axion-power-announces-order... http://www.rigzone.com/news/oil_gas/a/129019/Locomotive_Tech...
The reason the stock price is at 16 cents right now is because Axion has spent a decade developing the technology and is only beginning to see revenue. It has to raise money to continue operations. But the time is close.
A risky but potential very rewarding investment. Each potential market for their battery number in the billions.
More information can be found on Seeking Alpha via John Petersen's articles or the shareholders' blog at http://seekingalpha.com/instablog/1631091-axion-power-host/2...
Point me to car batteries that have exploded. And the raw materials for lithium batteries are cheap too, so they aren't going to be undercut much.
Weight is an important part of cars. Using 3x heavier batteries isn't going to go big. They could be useful for trains or stationary though.
Need more?
Lithium is one of the most expensive battery classes too... do I really need a source on this one. A Tesla battery costs 20k for a reason.
Weight is important for cars, but most cars already have lead-acid batteries. Furthermore batteries aren't a large portion of vehicle weight.
The reason lithium is used for electric cars is energy density. This is not a problem for hybrids.
Energy density is still useful for hybrids, especially PHEV. Earlier Prii use a very small lead-acid as 12V battery, but have a very large and heavy NiMH as the main pack. Doubling that weight is not a useful thing.
Telsa battery costs $20k because it goes >200 miles. What cost and weight would these batteries have in that same circumstance? (oh, it doesn't matter because they're only useful for hybrids, so why bring up Tesla?)
If those photos don't count as an explosion to you, I don't know what does.
(I'm aware that other parts would be flammable.)
Edit: not any part, but electrical systems do start fires.
Plugin hybrids and pure electrics need much larger batteries, so it certainly matters there, but for plain hybrids it's not such a big deal.
Assuming Pb-C is roughly comparable to Pb-Acid in mass density (since most of the weight is presumably in the Pb), then you'd need ~twice as much to match it in energy density.
I'm wondering how massive the battery packs will end up being on such a vehicle.
>The reason lithium is used for electric cars is energy density. This is not a problem for hybrids.
I don't understand what leads you to conclude this.
You are correct about the energy density, but the battery is used for regen breaking, engine start/stop, hotel loads, and in the case of Kia an electric supercharger. Essentially it provides smooth-over power, but the bulk will still come from gasoline.
Lithium is used in electric cars where they are the primary energy source. Lead carbon is only appropriate in micro to mild hybrids.
On the good side, hey its cheaper maintenance, long term. On the bad side this could encourage massive vendor lockin, such that a conventional ford f150 with a custom f150-only battery that "should" last for the life of the truck could charge nearly anything they want for it...
Compare the cost of a NiMH battery (3k or so) or a Li-ion battery (10-20k). The savings for a simple change far outclasses what heavy hybrids or full electrics can do dollar for dollar.
LiFePO4 can be bought for ~$.33/Wh
A flooded golf cart battery is the very cheapest per Wh, and they are about $.10/Wh assuming 100% capacity (which you can actually only use 50-80% of, boosting cost to $.13-.22/Wh).
You can spend a bunch of money on a full hybrid system and get large increases in fuel economy, or you can spend a small amount of money on a "mild hybrid" system and get a small increase in fuel economy. What he's saying is that, for the small amount of money involved, a 15% gain is pretty decent.