Stanford University researchers have discovered that aluminum may be the sought after alternative to volatile lithium commonly used in batteries.
Superior Recharging Capacity of Aluminum Battery
Stanford University professor Hongjie Dai has developed a high-performance aluminum battery that may replace lithium-ion batteries, which occasionally burst into flames. Unlike previous unsuccessful attempts with aluminum, his battery uses a graphite cathode along with an ionic liquid electrolyte. “The electrolyte is basically a salt that’s liquid at room temperature, so it’s very safe,” said Stanford graduate student Ming Gong, co-lead author of the study. The result is a safe and durable battery with superior recharging capabilities of more than 7,500 cycles without a loss of capacity, compared with lithium ion batteries, which last about 1,000 cycles.
While a lithium ion battery can take hours to recharge, the aluminum battery recharges in only one minute. Because of its capacity to be recharged quickly tens of thousands of times, it could be used to store renewable energy on the electrical grid, which could solve current problems of inconsistent renewable sources like wind and solar. “The grid needs a battery with a long cycle life that can rapidly store and release energy,” Hongjie Dai explained. “Our latest unpublished data suggest that an aluminum battery can be recharged tens of thousands of times. It’s hard to imagine building a huge lithium-ion battery for grid storage.”
Flexibility with Lower Cost Compared to Lithium Batteries
Another feature of the aluminum battery is its flexibility. It can be bent and folded to fit into flexible electronic devices. Aluminum is also a less expensive metal than lithium.
More Improvements in Cathode for Greater Power
Generating around 2 volts, higher than anyone has achieved before with aluminum, the aluminum battery still produces about half the power of a lithium ion battery. Because of this, the aluminum battery will need more improvement to replace lithium in high energy demand products like cell phones and laptops.
Hongjie Dai says that improving the cathode material could eventually increase the voltage and energy density. “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,” he said.