Anyone interested in electric vehicles understands that the most common problems faced by this class of vehicles include long charging times, limited driving range, charging station availability, and more. In an effort to make electric vehicles more popular with American consumers, researchers at Penn State University have made a breakthrough that reduces the recharge time of lithium-ion batteries to 10 minutes.
First author Xiaoguang Yang and his colleagues prepared a report of these findings for publication in Joule, a journal focused on sustainable energy science. It is argued that while there are still some hurdles to overcome, the long-held dream of practical electric vehicles with convenience comparable to gasoline-powered versions of cars may be closer to reality than people think.
In a home charging environment with a standard 120-volt outlet, an electric vehicle can be charged with enough electricity to support 2 to 5 miles per hour, while charging with a more powerful 240-volt outlet can allow the vehicle to travel 10 to 20 miles per hour.
Current fast charging stations charge much faster, with 20 minutes of charging able to supply 60-80 miles of additional range to the vehicle. However, fast charging can cause damage to the lithium plating (lithium metal formed around the positive electrode of the battery), greatly hindering the progress of fast charging research.
According to the report written by Yang and colleagues, the key to solving the above problem is to quickly heat the battery to 140 degrees Fahrenheit (60 degrees Celsius) in 30 seconds and maintain that temperature during the charging process. The specific measure is to install an inexpensive nickel foil on the battery. The charging process takes only a short time (e.g., 10 minutes) in the higher temperature environment, and the nickel foil prevents the formation of the battery’s lithium plating during this process.
The researchers found that after the above-mentioned initiatives were put in place, even with as many as 2,500 charges, the test battery still held 91.7 percent of its charge, which translates into a vehicle range of 500,000 miles, while the vehicle took no longer to recharge than a fueled vehicle.
Nevertheless, there are many obstacles to bringing this technology to the public level. First, heating batteries to a certain temperature and keeping them there for a period of time can cause environmental problems. If the batteries get too hot, they can degrade or, in rare cases, explode. However, if the battery temperature is too low, lithium plating can occur.
Secondly, the enabling of the above technology has to be put into new fast charging stations, or upgrades to existing ones. Eventually all battery manufacturers will have to incorporate nickel foil plating standards into their design aspects. Of course, given the rapid development of current technology, it is entirely possible that these issues will be resolved in a reasonable amount of time.