Engineers at Stanford University have developed a battery using alumium, graphite and urea which could provide an inexpensive means of energy storage.

The main ingredient of the battery’s electrolyte is urea which is already produced industrially in large quantities for fertilizers. The electrodes are made from abundant aluminum and graphite.

In 2015, the same Stanford laboratory made the world’s first rechargeable aluminum battery. This battery charged in less than a minute and lasted thousands of charge-discharge cycles. However, that version of the battery employed an expensive electrolyte.

The new version of the aluminum battery uses cheap and abundant urea as the base for the electrolyte. According to the Stanford engineers, this is the first time urea has been used in a battery.

Because urea isn’t flammable, it is a good choice for home energy storage, where safety is of utmost importance. However, the Stanford team sees grid storage as its primary application, because of the battery’s low cost, high efficiency and long cycle life.

Currently, these urea-based aluminum ion batteries can go through about 1,500 charge cycles with a 45-minute charging time. The research team is now investigating ways to extend the battery’s lifetime to at least 10 years.