Sharp is claiming the world's highest power density for a direct methanol fuel cell stack aimed at mobile equipment.

"Giving special attention to the power generation part's stack structure, Sharp has developed the three-dimensional highly integrated stack structure through the use of thin cells made by microfabrication," said Sharp. "This structure can be created by the alternate lamination of reed-shaped thin cells arranged in parallel at fixed intervals and reed-shaped porous spacers, with the cells and spacers running perpendicular to each other like a grid."

With this structure, uniform and continuous spaces are secured, said the firm, making it possible to increase the cell surface area per unit volume and smoothly circulate the air which oxidises the methanol's hydrogen.

The power density is 300mW/cm³ - about seven times greater than Sharp's previous generation.

"In the future, through continuing to pursue the development of this elemental technology, cell volume can be further miniaturised, and the creation of cells with the same volume but a longer lifespan than the currently mainstream lithium-ion batteries can be achieved," said Sharp.

Sharp revealed its stack at the Tokyo Fuel Cell Symposium this week.