Lithium-ion Gets Super Charged

Washington State University researchers are pushing lithium-ion to the max. They’ve developed a new technology that could triple the capacity of lithium-ion batteries, the ubiquitous power source for cell phones, laptops and other electronic devices. Grant Norton, a professor in the University’s school of mechanical and materials engineering, lead a team that has filed patents on the nanoscale-based technology, which also allows the batteries to re-charge many more times and faster than current models. They expect to bring it to the market within a year. Here’s the technical part, courtesy of WSU: the researchers developed an anode made of tin rather than the more commonly used carbon. Rechargeable lithium ion batteries are made up of two electrodes, the cathode and an anode. During charging, the lithium ions move from the cathode to the anode. The anode holds the lithium ions and stores the battery’s energy. When the battery is used, the ions move from the anode to the cathode, discharging electrons and creating an electric circuit. So the tin anode “has the potential to store almost three times the energy of graphite,” WSU says. Norton and postdoctoral researcher Uttara Sahaym developed the new tin anode material about a year ago while working on a project to mitigate “tin whiskers,” which are literally the tiny whiskers that grow on tin-plated electronics. These whiskers can sometimes grow as long as 10 millimeters and are a pesky problem in microelectronics because they create short circuits that can cause catastrophic damage. Yet, despite the fact that tin whiskers have been causing problems for more than 60 years, researchers have been unable to come up with ways to entirely avoid them. What the WSU researchers did was turn the whisker problem on its head, so to speak, to see if the growth of tin whiskers could be controlled, instead of trying to get rid of them. They applied their work to developing a tin-based anode for batteries; the result is a method for growing tin “nanoneedles” directly onto copper foil using a standard electroplating process. Electroplating means the tin-based anode costs less than regular graphite anodes—with triple the energy storage capacity. The new super lithium battery will look exactly the same as the current batteries, so that manufacturers won’t have to redesign their electronic devices to make room for a new battery, WSU says. The University’s research team has begun building and testing the batteries, an estimate of their eventual cost in the marketplace is premature, but it may not be exorbitant because they are cheaper to produce. This promises to be yet another advance in the struggle to keep power cords and chargers at bay and for the fast recharge. Call it lithium without limits, or at least with less limits than we have now. [Image: Nanoneedles from the WSU website]