Lithium-ion batteries have been a boon for the modern world -- they've replaced the heavier, single-use alkaline type in everything from wristwatches to jumbo jets. Unfortunately, these rechargeable cells are already struggling to keep up with our ever-increasing energy needs. But a new type of aluminum-ion battery developed at Stanford University is not only less explode-y than lithium, but also can be built at a fraction of the price and recharges completely in just over a minute. Best of all, "Our new battery won't catch fire, even if you drill through it," Stanford chemistry professor Dai Hongjie boasted in a recent release.
Unlike earlier aluminum batteries, which generally failed after only about 100 recharge cycles, Stanford's prototype can cycle more than 7,500 times without any capacity loss -- 7.5 times longer than your average li-ion. The aluminum-ion cell isn't perfect (yet) as it can only produce about 2 volts, far less than the 3.6V that lithium-ion an muster. Plus aluminum cells only carry 40 watts of electricity per kilogram compared to lithium's 100 to 206 W/kg power density. "Improving the cathode material could eventually increase the voltage and energy density," said Dai. "Otherwise, our battery has everything else you'd dream that a battery should have: inexpensive electrodes, good safety, high-speed charging, flexibility and long cycle life. I see this as a new battery in its early days. It's quite exciting."