FUEL CELL - Unserstanding electricity production.

The fuel cell was invented over 150 years ago (1839).

Sir William Robert Grove (1811-1896) and Christian Friedrich Schoenbein (1799-1868) are seen as the fathers of fuel cell technology. At the time, problems with the materials, along with the invention of the combustion engine and the electric generator conspired to prevent a rollout of fuel cell technology.

Not until the 1960s was the technology rediscovered by astronautics, where cost and lavish research programs don't matter. Due to increasing environmental pollution and our limited reserves of fossil sources of energy, new environmentally friendly fuels and efficient energy converters are in great demand. This serves to drive the research and development of fuel cells.

The way a fuel cell works is basically the opposite of the principle of an electrolysis cell.

In a fuel cell, chemical energy from hydrogen and oxygen (or air) is directly converted to electrical energy, i.e. without a combustion process. All fuel cells essentially consist of two electrodes (cathode and anode) and an electrolyte (medium for transporting the ions), which separates the two electrodes from each other.

Fuel cells are usually classified by the type of electrolyte used. Other traits they may differ in include Service Temperature, Efficiency, and Field of application.

PEM Fuel Cells

Like PEM electrolyzers, PEM fuel cells use a thin, proton-conducting polymer membrane as an electrolyte. Both sides of the membrane are coated with a layer of catalyst material, which partially differs from that of the electrolyzer.

The catalytic effects of the electrode (e.g. platinum) cause the hydrogen gas at the anode to break down into protons and electrons even at room temperature. The H+ ions (protons) traverse the proton-conducting Membrane to get to the cathode side. When the outer circuit is closed, the electrons travel to the cathode, thereby doing electrical work. As a result, water is produced the cathode (see diagram).

Individual fuel cells, summarized into a unit and connected with each other in series, result in a "stack" of cells.

The stacks' output can be varied as desired by adjusting the number of individual cells.