Why Lead-Carbon Batteries Will Deflate the Li-ion Bubble

 |  Includes: AXPW, WRK, XIDEQ
by: John Petersen

For over a year I've been cautioning readers that while lithium-ion batteries are glamorous, sleek, sexy and hot; they are about to face a formidable challenge from lead-carbon batteries that are a little bulkier and heavier, but offer competitive cycle-life and power for a tiny fraction of the cost.

To placate lithium fundamentalists and EV evangelists, I want to clearly state up front that lead-carbon batteries will probably not be the first choice for plug-in vehicles. Nevertheless, it is crystal clear that lead-carbon batteries will be the only sensible choice for micro, mild and full hybrid electric vehicles [HEVs] and many grid connected energy storage applications. A July 30th article from Earth2Tech titled, “Vinod Khosla On Why Lithium-Ion Batteries Are Overhyped” says it all, "The most important thing to remember is economic gravity – the cheapest thing ends up winning." What do you know; somebody far smarter than me who believes cheap beats cool.

As regular readers know, I recently participated in Infocast's Storage Week 2009 and served on three discussion panels. The core data for this article came from a slide-show that Patrick T. Moseley PhD, the president of the Advanced Lead-Acid Battery Consortium [ALABC], presented at the conference. While I've known about the surprising gains that come from the integration of advanced carbon materials into conventional lead-acid batteries for several years, the Moseley presentation is one of the first public documents to explore the details. A copy of Dr. Moseley's Storage Week presentation is available here. A complete archive of my articles on the energy storage sector is available here.

The media began paying attention to lead-carbon batteries in January 2008 when Autobloggreen reported the results of a road test that used a split-electrode lead-carbon "Ultrabattery" developed by Australia's Commonwealth Scientific and Industrial Research Organisation [CSIRO] to power a modified Honda Insight for 100,000 miles. The gist of the report was that in exchange for a weight penalty of 17 kg (37 pounds) and a fuel economy penalty of 2.8%, the Ultrabattery promised to shave up to $2,000 off the sticker price of a mild hybrid. Dr. Moseley's presentation took the Autobloggreen report a couple of steps further and provided the following graph of ALABC-sponsored cycle life testing that compared the Ultrabattery to a standard NiMH battery through 180,000 cycles at discharge rates of up to 5C and recharge rates of up to 4.5C using the European Council for Automotive R&D [EUCAR] Power Assist Profile (click on the graph for a larger image).

Similar cycle-life improvement was clear in another graph from the Moseley presentation that compared the performance of conventional lead-acid batteries with lead-carbon batteries that incorporated 2% carbon black and 2% graphite by weight (roughly 10% carbon by volume) in the sponge lead paste for the negative electrodes (click on the graph for a larger image). This particular series of tests compared the two battery strings at discharge rates of up to 4C and recharge rates of up to 3C using a duty cycle developed by BAE Systems for its hybrid transit bus program. Once again, the cycle-life gains were remarkable.

The real meat and potatoes of the Moseley presentation, however, was a slide that compared the performance and price of the Ultrabattery against (click on the graph for a larger image):

While I hate belaboring the obvious, a simple battery technology that surpasses USABC goals by a comfortable margin while reducing the sticker price of a mild hybrid by up to 10% is important in hard times because the majority of American and European consumers are carefully weighing car buying decisions and demanding real value. More importantly, lead-carbon batteries can be manufactured in existing plants without building a new manufacturing, supply chain and distribution infrastructure from the ground up. As a matter of simple capital efficiency, lead-carbon battery manufacturing will be an order of magnitude cheaper. It can also ramp up to required volumes in years rather than decades.

In a January 2009 article titled "Lead-Carbon: A Game Changer for Alternative Energy Storage" I reprinted a graph that showed the results of a series of partial state of charge [PSOC] cycle-life tests that Sandia National Laboratories performed in 2008 on five different batteries including a valve regulated lead-acid [VRLA] battery, two VRLA batteries with carbon enhanced pastes, an Ultrabattery, and an advanced lithium-ion (Li-FePO4) battery. I also reprinted Sandia's summary slide which concluded, "The new carbon enhanced negative electrodes in VRLA batteries have dramatically improved utility PSOC cycle-life up to a factor of 10."

In a follow-up article titled "Lead Carbon Batteries: A Game Changer for Alternative Energy Storage - Part II" I compared the relative strengths and weaknesses of the principal lead-carbon battery developers, both public and private. The four public companies that are actively developing lead-carbon battery technology are:

A 10-fold improvement in the performance of any technology is highly disruptive. The fact that lead-carbon batteries can do the work using cheap and plentiful raw materials from domestic sources and provide a product that is easily recycled in existing facilities is a game changer; particularly when both lithium-ion and NiMH batteries are based on imported raw materials that are likely to face substantial short-term supply constraints and will require the development of new recycling techniques and the establishment of a new recycling infrastructure.

In America we get up in the morning, we go to work and we solve our problems. NiMH and lithium-ion batteries cannot help the auto industry meet accelerated EU tailpipe CO2 emission standards and US CAFE standards because factories to make the batteries do not exist and even if they did, the world's mines couldn't extract the needed raw materials fast enough to satisfy the demand. Over the next decade there's a fair chance that lithium-ion batteries will complete the development and testing path described in an unpublished "pre-decisional draft" of a DOE report titled, National Battery Collaborative [NBC] Roadmap, December 9, 2008, which discusses the merits, risks and expected costs of an aggressive eight-year initiative to foster the development and facilitate the commercialization of lithium-ion batteries. However those future advances will have no impact on our current problems.

It's time to quit talking about the distant future and focus on solving today's problems.

DISCLOSURE: Author is a former director of Axion Power International (
AXPW.OB) and holds a large long position in its stock. He also holds a small long position in Exide (XIDE).