updated 12:25 pm EDT, Thu October 20, 2011
Greener tech fo Apple portables?
Two newly-published Apple patent applications suggest an unexpected Apple interest in hydrogen fuel cells, AppleInsider notes. The first, Parallel fuel stack architecture, suggests a way of arranging cells into a stack. A common problem with stacks is said to be a tendency toward a single point of failure in a connected series. There can also be many kinds of vulnerabilities, such as degradation of the electrolyte, accumulation of nitrogen in the anode, and water flooding in the anode or cathode. The reliability of stacks can go down as the number of cells grows, Apple comments.
The company's answer involves connecting fuel cells in a parallel setup using a power bus, also implementing a voltage-multiplying circuit. In theory this could increase reliability, while also supporting higher voltages.
The other application is meant to deal with weight. Bipolar plates in fuel cells are said to normally be built with conductive and corrosion-resistant materials such as stainless steel. Steel is heavy however, and while Apple doesn't propose a different material, it does argue that lining up cells in a monopolar configuration could allow sharing electrodes. This would reduce the number needed, as well as allow the use of lighter and thinner monopolar plates. As a consequence, fuel cells could become not only lighter but smaller, cheaper and/or more powerful than a regular bipolar cell stack.
Each patent filing dates back to April 2010. Apple may be considering fuel cells for future portable devices, such as MacBooks and iPads. While the company has often shown interest in more environmentally-friendly sources of power, however, most of its patents have explored solar panels, which have yet to be built into any Apple hardware.