Rechargable battery uses seawater to generate energy

Scientists have created the first rechargeable battery that uses seawater and freshwater to generate electricity.

If installed into every ocean-discharging river in the world (that's not a realistic scenario--just a frame of reference), the process could produce 2 terawatts, or about 13% of worldwide electricity use. As the researchers write, this battery is "simple to fabricate and could contribute significantly to renewable energy in the future."

Dubbed the "mixing entropy battery," this gadget generates current by harnessing the salinity difference between salt and freshwater. Freshwater is first funneled into the battery, which houses a positive and negative electrode.

After the battery is charged by an external energy source, the freshwater is switched out for seawater, whose added ions increase "the electrical potential, or voltage, between the two electrodes. That makes it possible to reap far more electricity than the amount used to charge the battery," according to Stanford News.

You can read more about the discovery here.