Discussion on:

Using salt water to power our batteries

Lithium is not commonly mined from ore. It is mostly extracted from brine or salt flats such as the Uyuni desert in Bolivia.

http://en.wikipedia.org/wiki/Lithium#Production

Could fill the world lithium demand as they become more common to supply fresh water. Solar desalination plants such as the ones in Australia and Saudi Arabia could keep batteries green and serve as a second stream of income for these plants along with other precious metals we commonly derive from salt water.

http://www.solardesalination.com.au/