Sharp increases fuel cell density

Sharp claims its latest direct methanol fuel cells (DMFC) for powering mobile equipment have the highest power density achieved so far for the technology.

At 0.3W/cc, the cells are about seven times denser than Sharp’s previous generation.

Like other fuel cells, DMFCs generate electrical power by the chemical reaction between hydrogen and oxygen. In the DMFC, methanol is supplied directly to the power generation stack of the cell and reacts with oxygen in the air.

Sharp has achieved the higher density in the new cells by shrinking the stack structure of the power generation element. The new 3D stack uses micro-fabricated thin cells laminated alternately with spacers arranged in a crystal-like grid.

This structure increases the surface area of the cell, exposing more of it to atmospheric oxygen.

Although Sharp sees scope for the cells to be miniaturised further, the next step will be to create cells of this density with longer lifespan, the company says.