Lead Acid Strikes Back?

[Puppyjump]

In my hours of wasted lifetime surfing the Net, when I could have been doing the dishes or loads of laundry, I stumbled on a potential for a revolution in battery technology: The Carbon Lead Acid chemistry. It appears that the main lead acid battery killer, sulfation, has been defeated, or at least tamed. The attached link shows many thousands of cycles (although only at a 10% DOD) of the carbon battery against a variety of other types, including LiFePO4.

Although the energy and weight advantages of Lithium are requirements for many types of effective EVs, many of us could get by with (presumably) inexpensive lead acid if only the batteries didn't fail so early.

Questions:

1)The author of the article owns stock in one of the research companies described, so is the information simply hype?
2) Is the cycle life still high if the DOD is 50% or more, a normal result of motive use (possible, I think, if the carbon still inhibits sulfation).
3) Will the mainstream lead acid battery makers adopt this chemistry? Presently, IMO, they rely on the batteries as being a consumable item. Trojan, for example, owns the golf cart and fork lift market, and those machines require fresh batteries every few years. The carbon type could effectively last forever, thus killing the replacement sales model.
4) Will Chevron, or another corrupt entity, simply buy up the patents (as with large format NiMH cells) and lock out the use of carbon batteries in motive applications?

http://seekingalpha.com/article/115257-lead-carbon-a-game-changer-for-alternative-energy-storage

 

[Lessss]

Until there is a product I can buy..........

 

[Puppyjump]

Until there is a product I can buy..........

Sad but true, hence my points #3 and #4.....

An example (besides the well known Large Format NiMH one)

1) So called "Stanford Lithium Nanowire Battery" capable of holding 10X the charge of existing ones, has had zero press (that I can find) since the press release in 2007. It turns out that the funding is now provided by Saudi Arabia (as revealed by Stanford's president during a recent NPR interview). How soon will this battery end up in an EV?
http://news.stanford.edu/news/2008/january9/nanowire-010908.html

 

[swbluto]

In the case of #4, you can only delay the inevitable upto 20 years under patent laws. So, yes, you may be miffed at the so-called evil oil companies, but realize that even if that's the case, their time will come.

 

[mclovin]

In the case of #4, you can only delay the inevitable upto 20 years under patent laws. So, yes, you may be miffed at the so-called evil oil companies, but realize that even if that's the case, their time will come.

Or buy it from China.

 

[torker]

10% dod isn't going to cut it. What really bothers me though is that companies like Chevron, Goldmen Sachs etc. can manipulate the market and stifle free trade.

 

[spinningmagnets]

Something doesn't sound right...(long post from drunken old fart warning)

His Sandia labs link only links to Sandias home page. Here's the Sandia carbon/lead PDF from Nov 2006

http://www.sandia.gov/ess/About/docs/craft.pdf

Claims: increases cycle life under "some" conditions. Charge and discharge currents improved...This is a far cry from the claims he is making in the article. From the otherpower.com site I have picked up a few things, allow me to share, and please correct me if I'm wrong.

Otherpower site is about using wind-gens and solar-PV to charge the large battery of an off-grid home. Batteries are typically Trojan flooded lead/acid (FLA), large and heavy. Two common reasons quoted for battery wont hold a charge anymore. Sulfation becomes crystallized so it wont reverse, and plates partially melted away.

Sulfuric acid is H2SO4, if you create an electrical imbalance (closed circuit allowing flow) the H2 separates from the SO4 (sulfates). As more and more sulfates begin coating lead plates, there is less plate surface area to allow chemical reaction to take place, so output voltage slowly and steadily goes down.

If battery is re-charged immediately, no sulfation sticking. If you leave a lead/acid battery in a discharged state for very long, the sulfates begin to crystallize, and will not recombine to re-form H2SO4 with the H2 thats suspended in electrolyte.

Equalizing (over)charge is electrolysis. Top off with water and the overcharge saturates the electrolyte with more new fresh H2 (acid has a propensity to absorb and hold H2, O2 will boil off). One plate may have discharged all its sulfates, but another plate has a little left on it. (voltage "slightly" lower in that cell, less surface area touching electrolyte).

Equalizing charge cleans sulfates off of all plate surface area, and also ensures theres plenty of H2 saturating the electrolyte (better to have too much H2 than too little).

Second reason is ionization of lead plates (they dissolve a little when current passes through them). Starter batteries for cars have very thin plates to pack a lot of surface area in a small package. ideally, after a 3-second drain to start engine, its immediately topped off.

Because of plate "melting" during charging, deep-cycle batteries (like Golf cart/Trojan home RE batts) have plates that are very thick, as thick as a finger. There is also space under the plates, to catch the ionized lead 'flakes" that drop to the bottom and build up. If they pile up too high, they will short the plates. You can see this on batteries with clear cases.

When battery is almost empty, it can charge with high amps, because theres a lot of sulfate and H2 available to absorb the charge and re-combine. But as it gets charged up, the charge must not only pass through the sulfates on the plates, it will pass through the now unsulfated portion of the plates, and will melt some of the lead away the entire time you're charging.

A smart charger that monitors the state of charge and adjusts the amps to match the available sulfates will pass very little current through the unsulfated plates. A cheap charger will give it whatever current it puts out until you turn it off. If you melt enough of the lead plates away, it will develop holes, and since then theres less surface area, its highest voltage will permanently be down.

The above information is for FLA's and I don't know how much of it might apply to SLA's or gel/lead-acid.

The article implied a lot of stuff that I simply don't see in the referenced PDF. Perhaps I found the wrong one, and there's a more recent break-through....

 

[TylerDurden]

SLA/FLA improvements will still benefit stationary applications best. Mobile apps really require modern chemistries' advantages.

Pb is heavy, suffers major Peukert, slow charging and is next to useless in the cold.

De-sulfators already seem to revive Pb batteries, so any "sulfation breakthrough" may be interesting, but not a panacea.