Yet Another Interesting Tweak for Lithium Batteries

Lithium batteries are almost a regular series around here; a quick search of the phrase "lithium battery" or "lithium batteries" returns well over a dozen posts on the subject.  This latest update comes from Design News (not the first battery post from them) author Elizabeth Montalbano on the discovery that adding asphalt to Lithium Ion batteries not only increased energy storage but allowed the batteries to be charged faster.

Researchers in the lab of James Tour, a Rice professor and chemist, have developed anodes that comprise porous carbon made from asphalt that showed significant stability even after more than 500 charge-recharge cycles, he said.

“They are very easy to make and have very high capacity—about 10 times more capacity than present battery anodes,” Tour told Design News . “Moreover, they charge in five minutes rather than two to four hours.”

Back in May, I quoted Charles Murray from Design News, saying,

While battery makers desperately try to figure out how to reach a specific energy of 450 Wh/kg (Watt-hours per kilogram), gasoline already offers 12,000 Wh/kg.

That problem still remains, although the Dr. Tour's batteries have more than doubled their specific energy to 943 Wh/kg from the cited 450 Wh/kg.  Now instead of having a 26.7:1 advantage, gasoline has a 12.7:1 advantage.  That has to be able to improve an EV's range (Electric Vehicle), but there are no practical numbers to base conclusions on. 

(Scanning electron microscope images show an anode of asphalt, graphene nanoribbons, and lithium (left) and the same material without lithium (right). The material was developed at Rice University and shows promise for high-capacity lithium batteries that charge 20 times faster than commercial lithium-ion batteries. (Image source: The Tour Group, Rice University))

Left for last in the DN article is the second most important aspect of this technique, which overcomes a common issue with Li-Ion batteries, their rather gauche habit of catching fire.

Testing also showed another improvement that the carbon brought to the batteries in that it mitigated the formation of lithium dendrites, or mossy deposits that can invade a battery’s electrolyte, researchers said. It’s these dendrites that can make batteries fail, catch fire, or explode because they can short-circuit the anode and cathode.

Recharging faster is very important for cars, as demonstrated in the recent evacuation of Florida for Hurricane Irma.  Twice the capacity may be even more important, since you'll get farther on a charge (Tesla Motors was reported to have issued an Over The Air software upgrade to some Teslas in the state to remove some software restrictions on the battery and increase their range).  Doing both of those while being a safer battery sounds like a real good change for the industry.  Before you ask, there's no mention of a patent or how Rice University manages such things.