The "safe" liquid fuel doesn't react to flames and would not start accidental fires during either storage or transport.

"The fuel we're normally using is not very safe. It evaporates and can ignite—and it's difficult to stop that," said Yujie Wang, a chemical engineering doctoral student at the University of California Riverside who co-authored a paper on the new fuel.

"It is much easier to control the flammability of our fuel and stop it from burning when we remove voltage."