How to Build a Better Battery

[OKIsItJustMe]

http://www.motherjones.com/news/feature/2008/05/it-keeps-going-and-going.html

A Charge to Keep

NEWS: The search for the perfect battery is fraught with obstacles—namely the laws of physics.

By Britt Robson
http://www.motherjones.com/toc/2008/05/index.html">May/June 2008 Issue

In a drab, cramped room at the back of Lee Hart's basement, there is a faint and somewhat eerie hum. More than a hundred large, mostly rechargeable batteries from around the world rise along the walls and sprawl across the floor. A few are hooked to machines with quivering meter needles measuring the amount and durability of their charges; the data are being fed into a 1987 Zenith XT computer with dual floppy disks stationed on a table in the corner. There are the traditional lead-acid batteries of the sort used in most cars. There's a stack of the nickel-metal-hydride batteries Hart salvaged from an EV1, the crushed vehicle that starred in the movie Who Killed the Electric Car? And there are the lighter, exponentially more expensive lithium-ion batteries.

Hart points to one of the latter—made in China, it's known as the Thunder Sky—and declares, "That would be a wonderful battery if it met the specs claimed by the manufacturer, and some of them do. But that tested out at about half the specs. You put this in a truck, it would be hard to notice. But if you have a stack of underperforming batteries in an electric car, it makes a difference."

A connoisseur of batteries and a debunker of the so-called breakthroughs that come around like clockwork every couple of years, Hart makes it his business to parse hype from performance. Whenever he hears about a new battery, the 58-year-old self-employed electrical engineer (he did lab work at Eastman Kodak and Honeywell) writes the company and asks for a prototype to be sent to his home in Sartell, Minnesota. "I'm a cheapskate, and sometimes they'll send me a free one," he jokes. So far, he still prefers lead-acid batteries. Using a life-extending charging system he designed himself, he's converting his third electric car to handle 14 of them; a buoyant pride creeps into his voice as he notes that most of the batteries are 8 to 10 years old. "Just like you don't feed an old dog puppy chow," he says, an old dog himself with the white tufts on the sides of his balding head combed up to resemble Mercury's wings, "you treat old batteries differently."

Hart has heard the dreamers wax on about a time when batteries will run for days on end, revolutionizing plug-in cars, windmills, and solar panels—just about any source of alternative energy would benefit from good batteries, which allow electricity to be stored and transported. He has sympathy for those visions. A motto of his hero, Thomas Edison, is inscribed on a favorite sweatshirt: "To invent you need a good imagination and a pile of junk." Like most electro-geeks who'd rather tinker than strut, he also adheres to Edison's practical DIY ethos, which explains the battery room and the small fleet of electric cars he has either retrofitted or built from scratch. His tests invariably reinforce what he and most everyone else familiar with the battery market have long known. When it comes to practical applications for sustainable energy, batteries are more of an Achilles' heel than a panacea, because we are running 21st-century technology with what is essentially 18th- or 19th-century chemistry.

...

(More at the link.)

[phantom power]

1. OK... as bad headline puns go, that's pretty good.

[tinrobot]

2. Thank goodness for people like him...

I've been doing research about converting a gas vehicle to an electric car, and the batteries are the most expensive and trickiest part of the equation. You really have to do the research. I'm glad people like him are doing testing like this, because it really helps people choose more wisely. When you spend thousands of dollars on batteries, you want to make sure your investment is a sound one.

I've heard a lot of bad things about the ThunderSky batteries, for example, because of independent testers like him. If you believed the ThunderSky specs, they have a great price/performance. But the real world performance is much lower, and they apparently have a very high failure rate.

[kristopher]

3. So...

So where did the 150 mile range on the current generation of EVs come from?

The article disparages lithium ion in a manner that certainly seems to be contradicted by the actions of the automobile industry. So seriously contradicted, in fact, that it makes this article seem pretty silly. I mean, the conclusions are based on a guy begging prototype batteries from manufacturers and then IF he gets them, testing them himself. Now, he seems to have been doing this a while, but I don't think the situation he 'tests' under, as described, inspires confidence in his 'findings'. I mean, are we to understand that he has access to the battery management software also?

Then there is the cost argument. Certainly it is valid as a temporary obstacle, but like any other product the cost is a function of manufacturing capacity. There is no intrinsic reason that lithium batteries should be expensive once sufficient manufacturing facilities are brought on-line. This is the stage we are in now.
One thing that I believe slows the process is the rate of improvement in the technology. It requires special incentives to get a company to invest heavily in a technology that is going to be outmoded in a few years. While the current technology delivers 150 miles per charge, the battery described in the link below is expected to realistically deliver 800-1000 miles per charge.

Stanford Report, December 18, 2007
Nanowire battery can hold 10 times the charge of existing lithium-ion battery

BY DAN STOBER
Courtesy Nature Nanotechnology silicon nanowires

Photos taken by a scanning electron microscope of silicon nanowires before (left) and after (right) absorbing lithium. Both photos were taken at the same magnification. The work is described in “High-performance lithium battery anodes using silicon nanowires,” published online Dec. 16 in Nature Nanotechnology.

Stanford researchers have found a way to use silicon nanowires to reinvent the rechargeable lithium-ion batteries that power laptops, iPods, video cameras, cell phones, and countless other devices.

The new technology, developed through research led by Yi Cui, assistant professor of materials science and engineering, produces 10 times the amount of electricity of existing lithium-ion, known as Li-ion, batteries. A laptop that now runs on battery for two hours could operate for 20 hours, a boon to ocean-hopping business travelers.

"It's not a small improvement," Cui said. "It's a revolutionary development."...

http://news-service.stanford.edu/news/2008/january9/nanowire-010908.html

If you'd like a copy of the research paper behind the article, just PM me.



Just some food for thought:
Lithium has an atomic weight of 3.
Nickel has an atomic weight of 28.
Lead has an atomic weight of 82.


Although still expensive compared to lead-acid batteries, small lithium-ion cells are in high volume production for portable electronics applications (e.g., laptop computers and cell phones) and are a mature product. Production volumes in excess of millions of cells per month have increased quality and reduced cost.
18650 cylindrical cells are being used as the basic building block of the battery packs. The use of small cells integrated into automotive battery size 24 V modules is advantageous beyond cost, since it allows great flexibility with different size modules while minimizing the non-recurring development costs of battery management systems. The modules are then connected in series and parallel to form the full vehicle pack. A schematic of the concept is shown in Fig.1.

Sophisticated battery management is being used to address safety.
The battery management system operates in a master/slave topology, where electronics reside in each 24 V module and communicate to a master controller in the vehicle. Close monitoring of battery parameters and disconnect contactors will enable safe operation and prevention of thermal runaway events. In addition, state of charge and state of heath monitoring will be included. Optical fiber serial data communications offers many inherent advantages including: voltage isolation of modules and electronics, elimination of high voltage signal wires, lack of RF signature and immunity from interference.
From: Lithium-Ion Batteries for Electric and Hybrid Electric Vehicles by Olsen etal 2006

[tinrobot]

4. What "current generation of EVs?"

Outside of the $100,000 Tesla, no major manufacturer is currently shipping an EV with 150 mile range, so I'm not sure what you mean by "current generation of EVs." A lot of EVs will come on the market in the next two years, but most of those will be lucky to hit a 100 mile range, much less 150 miles.

[kristopher]

5. The ones being road tested

The ones being road tested right now that are the prototypes for the coming launches have a range of 150.

[tinrobot]

6. Pure speculation.

Until these cars are actually sold and used by average people, the mileage figures are speculative.

Hopefully, we'll know in a year or two.

[kristopher]

7. Speculative doesn't result in announcements of product releases.

That is 'current generation' technology.

It's expected that the initial means of coping with longer distance travel is accommodation of extra battery packs. The only reason 150 has been selected is that it is the best trade-off for normal driving and shedding excess weight. Although probably not part of the first few models, (this part is my speculation) is that you'll be able to order variously configured battery packs just like you order different size engines.

[tinrobot]

8. It's not current generation until you can buy it.

The only car currently on the road with a proven 150 mile range at freeway speeds is the $100,000 Tesla.

I'd suggest you wait until 2009/2010 until the actual performance of the first crop of EVs is tested by third parties. I suspect the ones that actually get 150 miles on a charge will still be very expensive.

I once owned a laptop where the manufacturer claimed a 3 hour battery life. In real life, the battery lasted less than an hour. I wasn't the only one who had that problem, because there was a class action suit about the batteries and the manufacturer lost. Moral of the story : manufacturers can and will overstate battery life to sell laptops. I'm sure electric cars won't be much different. There's a lot of hype right now.

I'm optimistic about EVs, but also skeptical about some of these high numbers. People like Lee Hart in the original article are good, because they report actual numbers, which sometimes are a lot lower than the claims.

[kristopher]

9. Nothing like making up your own definitions

Where you derive the need that something to be available for immediate purchase in order for it to be 'current generation' is beyond me. Is there a special, secret dictionary you have tucked away somewhere?

The fact is that the Lion batteries being used in the field tests are mature technology - current generation. And according to a person I know driving one of the test cars, it is performing as expected. Next generation is 4-10X the power density of current generation.


Finally, no one said people like Hart aren't "good". That is hardly the point. People like Hart are just as likely to be wrong as they are to be right. I'll stick with peer reviewed literature. Perhaps that would be a better place for you to check with than non-peer reviewed manufacturer's data or non-peer reviewed garage hack data.