Block’s Indicator of Sustainable Growth

by Ray Block

Imagine if you could invent an advanced battery for transportation, which combines simultaneously  high power and high energy density. So that it can hold large amounts of energy, able to deliver it at high power, and to recharge rapidly.

If you can invent such a battery, you could become a billionaire overnight, with a great number of companies wanting to commercialise it.

No such ideal battery currently exists on the market.  But researchers at the Maryland NanoCenter at the University of Maryland have created an energy storage device with electrostatic nanocapacitors, which dramatically increase energy storage density by a factor of 10 over commercially available batteries. The device doesn’t sacrifice high power, and it also offers fast recharge. (Science Daily  March 22 2009) 

When such a device would be commercially available is not known. For now, the  lithium-ion battery is the current favourite. It stores large amounts of energy, but cannot provide high power or fast recharge.

The venture capitalist Vinod Khosla, the co- founder of Sun Microsystems, with two funds making up Khosla Ventures, has just raised US$1.05 billion mainly for clean tech ventures. As an investor in lithium-ion battery start ups Sakti3 and Se0o, Khosla says  “lithium-ion batteries are overhyped and will possibly be replaced. However, Khosla Ventures is backing the technology, because it is here today. We’re investing because there are good markets” (Greentechmedia July 30 2009)

What is concerning is that the price of an electric car will be initially far too dear at present, and the cost of the battery has a lot to do with it.

Demonstrating the significance of the next generation transportation future, the US Department of Energy in August 2009 distributed $2.4 billion to 48 companies, universities and other research institutions for research and development in advanced batteries and electric vehicles.

Daniel Sperling, founder of the Institute of Transportation, and a professor of engineering at the University of California at Davis is about to publish a study. This appears to indicate that even by 2035, adding a battery to a plug-in would add US$5,900 to an electric car.

But this doesn’t allow for the great amount of research and development currently proceeding, which will surely bring costs down. So that ultimately, the electric car will become a mass market people’s favourite.

The three big US auto companies, GM, Ford and Chrysler have formed the United States Advanced Battery Consortium, with a long range plan for a car battery, which will cost as little as  $20 per kilowatt hour(kWh). This compares with the current cost for a lithium-ion battery in  electric vehicle prototypes of $1,000 per kWh.

Ted Miller, senior manager of energy storage research at Ford Motor spoke at an energy storage conference in August 2009 at IBM’s Almaden Labs in California. Miller said “there are foreseen limits on lithium -ion technology.”

One of his charts showed a 2017 endpoint for squeezing improvements out of the current technology. “That will limit everything from driving range to how much we can decrease the package size,” given that designing batteries for passenger cars is an important consideration.

Miller’s and IBM’s long range battery substitute  for the lithium-ion is the lithium-air battery. But on a shorter time span, the lithium-sulphide battery may slot in as the battery of choice for electric vehicles.

The lithium- sulphur battery has a theoretical potential to deliver about 2,600 watt hours per kilogram, versus lithium-ion’s potential of 584 watt hours per kilogram. But as can be expected, at this stage of research and development, there is a major drawback. The device tends to operate only at high temperatures.

Jeff St John of Greentech (August 27 2009), said that Elton Cairns, a professor at the University of California at Berkeley is a supporter of lithium -sulphur batteries. Research so far has yielded better energy densities than lithium-ion batteries, but it needs to increase cycle life.

Sion Power of Tucson, Arizona, which is in partnership with the German chemical company BASF, plans to release a commercial version  lithium -sulphur battery within two years.

But the ultimate battery, which simultaneously provides high power and high energy density may well be the lithium-air battery, or possibly the zinc-air battery.

Theoretically, an IBM researcher says that a lithium-air battery could provide about 10 times the energy density of a lithium-ion battery.

Jeff St John (July 27 2009) reported that researchers at Japan’s Institute of Advanced Industrial Science and Technology(AIST) have come up with a solution for developing such a battery at reasonable cost.

The blog Gas 2.0 says that the AIST researchers believe a driver of an electric vehicle equipped with an lithium-air battery would make use of  a revolutionary new cassette refilling system, and then continue driving without waiting for the batteries to be recharged.

The alternative to the lithium-air battery is a zinc-air battery, where a Swiss company has formed a US subsidiary to tap Department of Energy funds for commercialising the device. The subsidiary ReVolt Technology has set up shop in Portland, Oregon to build a factory to make the unit.

The claim is that the zinc-air battery delivers more than twice the energy of a lithium-ion battery. And because it uses naturally abundant zinc, it has low manufactuing costs, which are desirable for it to be the low cost power system for the people’s electric vehicle.  

Zinc batteries are used in hearing aids and in computers, so it’ s a stable metal and worth research and development.

Lithium-ion  batteries have the current inside running, because they store large amounts of energty but