Recharge time is a huge issue for electric car developers. At 220V, most battery-electric cars take about six to eight hours to recharge. Cut the voltage to 110V, and the recharge time doubles.
Now, though, a University of Illinois professor and his research group say they’ve found a battery structure that’s more conducive to fast recharging. Paul Braun, a professor of materials science and engineering at the school, has created a fast-charging battery by employing an active thin film material wrapped in a three-dimensional structure. By doing so, the group says it can achieve both high capacity and large current.
“They have demonstrated battery electrodes that can charge and discharge in a few seconds, 10 to 100 times faster than equivalent bulk electrodes, yet can perform normally in existing devices,” a University of Illinois press release said.
The group’s battery structure reportedly solves the main drawback to fast re-charge. Up to now, performance of conventional batteries has degraded when they are rapidly charged. Materials scientists and electrochemists have long known they could use thin films to speed the recharge, but they’ve also known that thin films fail to store much energy, mainly because they lack volume.
But by wrapping the thin film in the three-dimensional structure, Braun’s groups said they can get the best of both worlds.
“Most batteries store a reasonably large amount of energy, but they can’t provide or receive energy rapidly,” Braun said. “This does both.”
The group is said to have demonstrated the technology in nickel-metal hydride and lithium batteries. Test batteries have reportedly been 90%-recharged in two minutes, which would mean an electric car might one day be recharged in about the same amount of time it takes to refill a gas tank.