The television ads are appearing more frequently and the cars they tout more recognizable. Within a few months public charging stations will start to spring up around central Illinois as electrical vehicles (EVs) enter the American consumer consciousness as a viable choice for motorists. And those EVs don’t exist without batteries, just like laptops, cell phones, and almost every other one of the electronic devices that seem essential to life in the 21st Century.
With the factors of climate change, the energy crisis, and consumer demand as incentives, the government – principally the Department of Energy (DOE) — is pushing for big technology advances in batteries, or the more generic term, electrical energy storage (EES) systems. Beckman Institute researchers are at the forefront of these research efforts when it comes to creating battery systems that are longer lasting, more reliable, more powerful, faster, and safer. That is especially true when it comes to advancing battery technology for electrical vehicles.
Electrical vehicles have been around for awhile, but mostly they have been the transportation choice of those concerned with the environment and the hobbyist. Now there is a push by both manufacturers and government (in the form of tax credits and research grants) to bring them to a mass marketplace.
A new ad campaign for an all-electric car, the Mitsubishi i EV, is touting Bloomington-Normal, Illinois, as a model EV community. The car is already being sold by dealerships in California, and is slated to hit the roads locally this spring. The Chevrolet Volt is an electrical vehicle with a gas generator in reserve for longer distance driving; there are more than 6,000 already in use on American roadways.
Several faculty in Beckman’s Molecular and Electronic Nanostructures research theme have made recent discoveries that have the potential for greatly advancing battery systems, including creating self-healing technology for EES ( Scott White, Nancy Sottos and Jeff Moore), and developing ultrahigh energy and power density batteries ( Paul Braun, Harley Johnson, and Sottos).
White, Sottos, and Moore are members of Beckman’s Autonomous Materials Systems group who have developed self-healing materials systems based on microcapsule and vascular technology that autonomically responds to damage with healing agents. Now they are applying some of those same techniques toward self-healing for batteries. Their work is part of a new DOE-funded Center for Electrical Energy Storage (CEES) that seeks to create future battery technology for EVs that is both longer-lasting and safer.
But electrical vehicles are already coming off assembly lines, General Motors and Mitsubishi wagering a lot on their success. Fires in lithium-ion batteries — the most common battery technology in use today — have plagued electronic devices, and have occurred in delayed fashion following crash tests of the Volt.
“There is a huge amount of pressure to solve problems right away because these are being rolled out,” White said. “As we’ve just seen with the Volt fire, the more these cars are out there, the more you’re going to see these reports. If electric cars come out and have safety problems and have major loss of life and property, the public is just not going to go that route.
“And we have to in order to solve the energy problem. We can’t fail. We’ve got to pay really serious attention to safety issues and make sure that is never going to be a problem.”
Self-healing Methods for Making Batteries Safer
Last year two Volts caught fire following crash tests — in one case, days and in another, weeks after the test — by the National Highway Traffic Safety Administration; later, the lithium-ion battery that powers the car was determined to be the culprit. According to the Associated Press story on one incident, an “NHTSA investigation concluded the crash test damaged the battery, which later led to the fire. Lithium-ion batteries, which are used in a vast array of consumer electronics, have a history of sometimes catching fire when damaged.”
