Faster Li-Ions as Easy as A123?

Despite the fact that batteries were probably invented several thousand years ago, and have been used in cars since the late 19th century, they remain functionally primitive, messy devices. Compared to the absolutely amazing hydrocarbons that power today’s transportation, batteries are klunky, dirty, heavy, and slow to replenish, and, well, feel free to add any faults that I’ve missed, or make them up if you want. Mock the balky battery! It certainly deserves it.

It’s actually a shame though, because if only the battery would smarten up, and lighten up, and clean up, the green future of automobiles might loom nigh, peak oil could become another footnote in the history of technological advance, and four dollar gasoline could be a forgotten nightmare. Imagine your favorite clean electricity source replenishing the new magic batteries at your home, office, or Main Street charging station–quickly, quietly, and cleanly.

Now two MIT researchers have tweaked the technology just enough to hang a few rays of hope on. Gerbrand Ceder, the Richard P. Simmons professor of materials science and engineering reported an advance in the March 12 Nature that could result in charging lithium ion batteries being quicker than filling up your gas tank––one that could render Better Place battery swap-out stations obsolete.

The problem that Ceder was addressing is that while lithium rechargeables can store a lot of energy per unit weight, the charge and discharge rates are slow. Half a decade ago, Ceder et al. made the unexpected discovery (through computer calculations) that charge and discharge should move far more quickly. They then determined that the sleepy rate of charge transfer had to do with the fact that the ions were slow to find entry points into the surface of the battery. They developed a coating that in rough analogy gives the ions a highway into the entry points.

The technology could make it possible to charge your consumer electronics in seconds, and could give EVs charging times comparable to a fillerup. A123 Systems, the Watertown, Massachusetts, advanced battery company, has an option to license the technology.

The second new device from MIT, reported April 2 online in Science by Angela Belcher et al. (whose collaborators included Ceder), is perhaps first and foremost a green way to make the cathodes on lithium ion batteries. In earlier work, Belcher devised a similar way to make the anodes. (Click here and scroll down to “Fashioning Conductive Nanowires”). The challenge with cathodes is that the materials must be highly conducting, but most candidate materials are highly insulating.

While most batteries require very high temperatures in the fabrication process, along with noxious materials, Belcher’s cathodes are fabricated below room temperature by harmless viruses of a sort that normally infect bacteria, the name of which (M13) has nothing to do with British motorways.

The virus, long and wiry at 880nm x 6nm, is engineered to grab carbon nanotubes at one end, and to collect iron phosphate, a conductor, along its length, assembling them into cathode.

“We showed we had really good performance. If this could be scaled up, it could be used in your Prius,” says Belcher, who drives one, and who is the Germeshausen Professor of Materials Science and Engineering and Biological Engineering. “And maybe, maybe, it could be used for plug-in EV batteries,” says Belcher, promising nothing. Then we could all go back to worrying about health care reform.