Scientists at Stanford University have invented the first high-performance aluminum battery that’s fast-charging, long-lasting and inexpensive. Researchers say the new technology may replace existing storage devices, such as alkaline batteries, which are bad for the environment, and lithium-ion batteries, which occasionally burst into flames. The new battery won’t catch fire, even if you drill through it.
An aluminum-ion battery consists of two electrodes: a negatively charged anode made of aluminum and a positively charged cathode. For the experimental battery, the Stanford team placed the aluminum anode and graphite cathode, along with an ionic liquid electrolyte, inside a flexible polymer- coated pouch.The electrolyte is basically a salt that’s liquid at room temperature.
One important thing about this battery is ultra-fast charging.Smartphone owners know that it can take hours to charge a lithium-ion battery. But the Stanford team reported “unprecedented charging times” of down to one minute with the aluminum prototype.
Durability is another important factor. Aluminum batteries developed at other laboratories usually died after just 100 charge-discharge cycles. But the Stanford battery was able to withstand more than 7,500 cycles without any loss of capacity. This was the first time an ultra-fast aluminum-ion battery was constructed with stability over thousands of cycles. By comparison, a typical lithium-ion battery lasts about 1,000 cycles.
Another feature of the aluminum battery is flexibility. You can bend it and fold it, so it has the potential for use in flexible electronic devices. Aluminum is also a cheaper metal than lithium.
In addition to small electronic devices, aluminum batteries could be used to store renewable energy on the electrical grid. The grid needs a battery with a long cycle life that can rapidly store and release energy. The latest unpublished data suggest that an aluminum battery can be recharged tens of thousands of times.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.
Millions of consumers use 1.5-volt AA and AAA batteries. This new rechargeable aluminum battery generates about two volts of electricity. Aluminum batteries are safer than conventional lithium-ion batteries used in millions of laptops and cell phones today.
This research is published in the advance online edition of the journal Nature.
