Battery advances require integration of research with manufacturing and engineering

Countless breakthroughs have been announced over the last decade, time and again these advances failed to translate into commercial batteries. One difficult thing about developing better batteries is that the technology is still poorly understood. Changing one part of a battery—say, by introducing a new electrode—can produce unforeseen problems, some of which can’t be detected without years of testing.

LeVine describes what went wrong with Envia. In 2006 Envia had licensed a promising material developed by researchers at Argonne National Laboratory. Subsequently, a major problem was discovered. The problem—which one battery company executive called a “doom factor”—was that over time, the voltage at which the battery operated changed in ways that made it unusable. Argonne researchers investigated the problem and found no ready answer. They didn’t understand the basic chemistry and physics of the material well enough to grasp precisely what was going wrong, let alone fix it, LeVine writes.

With its experimental material for the opposite electrode, this one based on silicon, Envia faced another challenge. Researchers had seemingly solved the major problem with silicon electrodes—their tendency to fall apart. But the solution required impractical manufacturing techniques.

When Envia made its announcement in 2012, it seemed to have figured out how to make both these experimental materials work. It developed a version of the silicon electrode that could be manufactured more cheaply. And through trial and error it had stumbled upon a combination of coatings that stabilized the voltage of the Argonne material.

The results Envia had reported for its battery couldn’t be reproduced, understanding the problem became crucial. Even tiny changes to the composition of a material can have a significant impact on performance, so for all Envia knew, its record-setting battery worked because of a contaminant in a batch of material from one of its suppliers.

The story of Envia stands in sharp contrast to what’s turned out to be the most successful recent effort to cut the price of batteries and improve their performance. This success hasn’t come from a breakthrough but from the close partnership between Tesla Motors and the major battery cell supplier Panasonic. Since 2008, the cost of Tesla’s battery packs has been cut approximately in half, while the storage capacity has increased by about 60 percent. Tesla didn’t attempt to radically change the chemistry or materials in lithium-ion batteries; rather, it made incremental engineering and manufacturing improvements.

Tesla claims that it is on track to produce a $35,000 electric car with a roughly 200-mile range by 2017—a feat that’s equivalent to what GM hoped to achieve with Envia’s new battery. The company anticipates selling hundreds of thousands of these electric cars a year, which would be a big leap from the tens of thousands it sells now. Yet for electric cars to account for a significant portion of the roughly 60 million cars sold each year around the world, batteries will probably need to get considerably better. After all, 200 miles is far short of the 350-plus miles people are used to driving on a tank of gasoline, and $35,000 is still quite a bit more than the $15,000 price of many small gas-powered cars.

At some point, radical changes such as the ones Envia envisioned may be needed. But the lesson from the Envia fiasco is that such changes must be closely integrated with manufacturing and engineering expertise.

That approach is already yielding promising results with the Argonne material that Envia licensed. Envia’s battery operated at high voltages to achieve high levels of energy storage. Now battery manufacturers are finding that using more modest voltage levels can significantly increase energy storage without the problems that troubled Envia

SOURCES- MIT Technology Review

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