The stability of the new materials suggests a way to increase energy density at the pack level

The company then turned its attention to the opposite electrode, which is usually made of graphite. Researchers decided to use silicon, which can store far more energy but typically works for only a short number of charges, since it swells and cracks. Envia addressed these issues by using a porous form of silicon, which is better able to tolerate expansion and contraction, and by mixing the silicon with various forms of carbon, including carbon fiber and graphite.

The carbon is meant to provide a path for electrons to take through the material, bridging gaps that form as the silicon cracks. The researchers also had to modify the electrolyte to keep it from breaking down at the high voltage levels seen in the battery cell.

The stability of the new materials suggests a way to increase energy density at the pack level, Chamberlain says. The current Volt battery pack is designed with extra energy-storage capacity to ensure that the car’s performance doesn’t suffer much as the battery ages. He says if future batteries lasted without needing the extra capacity, this would decrease the cost of the pack.

“This is probably the most capable cathode material that we have seen out there, and that’s the reason that we think it’s really critical that we get started working on this material now, so that we can get it on the road,” Lauckner says. “It’s going to take some years to further develop it and validate it. The idea is we want to get this on the road for the next generation of battery packs that come out.”

Patel says the batteries could use air cooling rather than liquid cooling, which would make them cheaper and lighter. The company is also developing battery management electronics and software to prevent overcharging or undercharging, problems that can compromise battery life, he says. Leyden recently received a $2.96 million grant from California on a project to produce 10 car battery packs per month.

The new electric sports cars use conventional lithium-ion batteries for the same reason they’re now used in laptop computers: they store a lot of energy in a small, light package. But several factors have kept these batteries out of widespread use in vehicles.

One is cost — the Venturi Fetish sports car, for example, sells for over $500,000. The batteries are also tricky to operate safely in the large quantities needed in vehicles — overheating or damage can cause them to catch fire or explode (as led to last year’s Apple PowerBook battery recall). These batteries also have a short lifespan, losing their ability to hold a charge well over time, as anyone who’s owned a laptop for a few years knows.

New lithium-ion battery materials, however, may change all this. Safer chemistries have recently allowed manufacturers such as Milwaukee Electric Tool in Brookfield, WI, and DeWalt Industrial Tool of Baltimore MD, to start using lithium-ion batteries in abuse-prone power tools. The new materials could also extend the batteries’ lifetime, reduce their cost, and improve their performance.

As the production scale increases and costs come down, Liquid Metal plans to serve larger-scale markets, such as buying cheap electricity at night and selling it in the middle of the day, when prices are higher. Because the technology is flexible the company can decide how to use its battery capacity, always picking the most lucrative market.

Liquid Metal plans to take advantage of two opportunities created by the government. The first is actually a product of deregulation: the government set up framework for establishing open markets for power. This allows the company to register as an independent power provider without going through a utility or getting regulators to allow utilities to charge for the service.

Even if problems with batteries are overcome in the lab, these technologies face obstacles to being commercialized. To drive down costs, battery makers are turning to applications other than electric vehicles and the grid to get new technologies off the ground, applications such as microelectronics, power tools, and race cars. Plug-in hybrids can also help serve as a bridge to electric vehicles.

One such place is the monitoring of military equipment. “Everything the Department of Defense puts out has to have antitamper protection so that if someone gets their hands on the seeker head of a missile, or an entire aircraft, it would be very difficult to reverse-engineer it,” says Christian Adams, a chemist at Lockheed Martin Missiles and Fire Control.

The memory chips that control such antitamper systems, says Adams, require very low continuous power over a long time. Military specifications also require that these devices withstand extreme conditions that normal batteries can’t tolerate: they must operate in temperatures from -65 to 150 ?C and withstand high-frequency vibrations, high humidity, and blasts of salt. “If the battery freezes out or dies out, the memory circuit loses its configuration,” and the device fails, says Adams.

In the past, using lithium-ion batteries in a motorcycle would have been a bad idea because of safety concerns. Conventional lithium-ion batteries–the type used now in laptops and cell phones–can overheat and explode, which has led to massive product recalls and at least one death. In one of the electrodes, those batteries use cobalt oxide, a material that makes it possible to cram a lot of energy into a battery. But cobalt oxide is also volatile.

But the new lithium-ion motorcycles rely on advanced lithium-ion chemistries that don’t catch fire. The new batteries use phosphate- rather than oxide-based electrodes. It takes much higher temperatures to release oxygen from phosphates, making the batteries very difficult to set on fire, even in safety tests designed to do so.

But Kelty says the economics of recycling depend largely on the chemistries of the lithium-ion batteries being used. He adds that lithium is currently one of the least valuable metals to retrieve. For example, the lithium in a Tesla Roadster battery pack would represent roughly $140 of a system with a replacement cost of $36,000. For most lithium-ion batteries, the lithium represents less than 3 percent of production cost.

“The lithium part is a really negligible cost when you compare it to other metals; nickel, cobalt, those are going to be the biggest drivers [of recycling],” says Kelty, adding that Tesla actually makes money by recycling just the nonlithium recycled components of its batteries. “So while we’ve been reading plenty of articles about the industry running out of lithium, it’s totally missing the mark. There’s plenty of lithium out there.”

Lower-energy batteries often have safety features that make them attractive for use in cars. Sujeet Kumar, Envia’s president and CTO, says the company’s batteries have passed nail puncture tests, one key test of battery safety. If it begins to overheat, the material gives off oxygen, which feeds reactions that lead to “thermal runaway” and flames.

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