A doctoral student in Los Angeles has developed a fuel cell 50 to 100 times more efficient than existing portable batteries.

Ahn Jeong-min on Wednesday said his new product lacks the weakness of curent fuel cells, and create its own heat when generating electric energy and thus sharply reduces the procedural temperature.

Potential commercial uses of his fuel cell include portable electronic gadgets that run on lithium ion batteries such as cell phones, cameras and PDAs.

Ahn's research has been published in the science journal Nature.

Ahn is currently pursuing a Ph.D. in aerospace engineering at the University of Southern California.