NEC develops notebook fuel-cell battery

The firm hopes to be able to run for 40 hours in two years' time and fuel-cell mobile computers are expected to end the current reliance on rechargeable lithium-ion batteries. The cell, weighing two kilograms when built in a computer, will be available to notebook makers in about two years. It can already operate for five hours on 300 cubic centimeters of methanol, according to the report.

Fuel cell technologies face several hurdles before they can garner widespread adoption--problems, for example, with delivering the fuel, miniaturization and the cost of the materials needed to build efficient fuel cells.

Toshiba, another fuel cell developer, said it dealt with the problem of miniaturization by altering how the methanol is diluted with water to achieve the optimal concentration to power the cells. Methanol, the company said, delivers power most efficiently when it is mixed with water in a 3 percent to 6 percent methanol concentration. Storing the fuel at that concentration requires a tank that is too large for mobile devices.

The company said it overcame this problem by developing a system for methanol to be diluted by the water produced as a by-product of the power-generation process, which allows the methanol to be stored at a much higher concentration and in smaller fuel tanks.

Current fuel cells produce energy by creating a chemical reaction between methanol and oxygen. Electrodes draw those substances toward a plastic membrane, and when they come in contact with the membrane, the methanol breaks down and releases electrons, which are then funneled to power the host device. The byproducts of the reaction eventually recombine with the electrons to form water and carbon dioxide.

News.com's Sandeep Junnarkar and Michael Kanellos contributed to this report