History

The history of the fuel cell can be traced back to the nineteenth century and the work of the British judge and scientist, Sir William Robert Grove. His experiments in 1839 on electrolysis - the use of electricity to split water into hydrogen and oxygen - led to the first mention of a device that would later be termed the fuel cell.

Grove reasoned that it should be possible to reverse the electrolysis process and generate electricity from the reaction of oxygen with hydrogen. The term 'fuel cell' was coined by the chemists Ludwig Mond and Charles Langer in 1889 as they attempted to build the first practical device using air and industrial coal gas.

It soon became apparent that there would be many scientific hurdles to overcome if this technology were to be commercialized and early interest in Grove's invention began to diminish. By the end of the century the advent of the internal combustion engine and the widespread exploitation of fossil fuels meant that the fuel cell was relegated to the status of a scientific curiosity.

The next major chapter in the fuel cell story was written by an engineer at Cambridge University, Dr Francis Thomas Bacon, a direct descendent of his 17th century philosopher namesake. In 1932 Bacon resurrected the machine developed by Mond and Langer and carried out a number of modifications to the original design. These included replacing the platinum electrodes with less expensive nickel gauze. He also substituted the sulphuric acid electrolyte for alkali potassium hydroxide, a substance less corrosive to the electrodes. This device which he named the 'Bacon Cell' was in essence the first alkaline fuel cell (AFC).

It would however prove to be another 27 years until he could produce a truly workable fuel cell. In 1959 Bacon demonstrated a machine capable of producing 5 kW of power, enough to power a welding machine.

The recent history of the fuel cell can be thought of as beginning in the early 1960s. A new US government agency, the National Aeronautics and Space Administration (NASA), was looking for a way to power a series of upcoming manned space flights. NASA had already ruled out using batteries as they were too heavy, solar energy as it was too expensive and nuclear power as it was too risky and began to look around for an alternative. The fuel cell was lighted upon as a possible solution.

This search led to the development of the first Proton Exchange Membrane (PEM). GE went on to develop this technology with NASA, leading to it being used on the Gemini space project. This was the first commercial use of a fuel cell.

The aircraft manufacturer Pratt & Whitney licensed the Bacon patents for the alkaline fuel cell. The company modified the original design in order to reduce the weight and developed a cell that proved to be longer-lasting than the GE PEM design. As a result P and W won a contract from NASA to supply these fuel cells to the Apollo spacecraft and alkali cells have since been used on most subsequent missions, including the Space Shuttle flights. An additional benefit of using fuel cell power is that they produce drinkable water as a by-product.

During the 1970s, fuel cell technology was developed for systems on Earth. The oil embargos of 1973 and 1979 helped to push along the research effort of the fuel cell as the U.S. Government was looking for a way to become less dependent on petroleum imports.

A number of companies and government organizations began serious research into overcoming the obstacles to widespread commercialization of the fuel cell. Throughout the 1970s and 1980s, a large research effort was dedicated to developing the materials needed, identifying the optimum fuel source and drastically reducing the cost of this technology.

During the 1980s, fuel cell technology began to be tested by utilities and automobile manufacturers. Technical breakthroughs during the decade included the development of the first marketable fuel cell-powered vehicle in 1993 by the Canadian company, Ballard. 

	AFC	DMFC	MCFC	PAFC	PEMFC	SOFC
Electrolyte	Potassium hydroxide	Polymer membrane	Immobilized Liquid Molten Carbonate	Immobilized Liquid Phosphoric Acid	Ion Exchange Membrane	Ceramic
Operating Temperature	60-90ºC	60-130ºC	650ºC	200ºC	80ºC	1,000ºC
Efficiency	45-60%	40%	45-60%	35-40%	40-60%	50-65%
Typical
Electrical	Up to 20 kW	< 10 kW	> 1 MW	> 50 kW	Up to 250 kW	> 200 kW
Power
Possible Applications	Submarines, spacecraft	Portable applications	Power stations	Power stations	Vehicles, small stationary	Power stations

Alkali Fuel Cell History

Francis Thomas Bacon (1904-1992) of Britain began experimenting with alkali electrolytes in the late 1930s, settling on potassium hydroxide (or KOH) instead of using the acid electrolytes known since Grove's early discoveries. Over the course of the following twenty years, Bacon made enough progress with the alkali cell to present large scale demonstrations.

One of the first of these demonstrations consisted of a 1959 Allis-Chalmers farm tractor powered by a stack of 1,008 cells. With 15,000 watts of power, the tractor generated enough power to pull a weight of about 3,000 pounds. Allis-Chalmers maintained a research program for some years, building a fuel cell powered golf cart, submersible, and fork lift.

Union Carbide also experimented with alkali cells in the late 1950s and 1960s. Building on the work done in the 1930s. In the early 1960s, aircraft engine manufacturer Pratt & Whitney licensed the Bacon patents and won the National Aeronautics and Space Administration (NASA) contract to power the Apollo spacecraft with alkali cells. Its successes notwithstanding, alkali technology has challenges ahead. Current alkali fuel cells still demand very pure hydrogen and expensive platinum catalysts, and other kinds of fuel cells are mounting stiffer competition.

In the 1980s Siemens (Germany) built a 48kW system consisting of eight 6kW stacks, which was tested as part of a German defense program. In addition, a 40kW AFC system was constructed in the 1980s by Elenco (Belgium/Netherlands), which was mounted on a trailer and used as a power source in geological field-work

In July 1998, the Zero Emission Vehicle Company (ZEVCO) launched its first prototype taxi in London, England. The taxi uses a 5,000-watt alkali fuel cell that produces no noxious fumes and much less noise than traditional internal combustion taxis.

Phosphoric Acid Fuel Cell History

Experimenters have used acids as electrolytes since the time of William Grove's first gas battery in 1842 – he used sulfuric acid. But phosphoric acid, a poor conductor of electricity, was not as attractive, and PAFCs were slower to develop than other types of fuel cells.

In the late 1960s and 1970s, major advances in electrode materials and lingering problems with other types of fuel cells spurred new interest in PAFCs.

In the mid 1960s, the U.S. Army explored the potential for PAFCs that ran on "logistic fuels," meaning fuels commonly available to units in the field. For the Army's tests, a cell was produced by Allis-Chalmers and used an Engelhard Industries steam reformer and an electrical inverter from Varo, Inc.

An industry partnership known as TARGET, or Team to Advance Research for Gas Energy Transformation, Inc., also supported some significant research. Sponsored primarily by Pratt & Whitney and the American Gas Association, TARGET research led to fuel cell power plants from about 15 kw in 1969 to nearly 5 mw in 1983.

The energy crises of the 1970s inspired researchers at Los Alamos National Laboratory to begin studying fuel cells. With an eye toward developing electric vehicles, they designed a golf cart powered by a phosphoric acid fuel cell.
H-Power, Georgetown University, and the U.S. Department of Energy adapted a 50 kw Fuji Electric PAFC for transit buses and began running these buses in 1994. Four years later, Georgetown, Nova BUS, and the U.S. Department of Transportation began tests on a bus powered by a 100 kw PAFC from International Fuel Cells Corporation (a joint venture of Toshiba and United Technologies). PAFCs currently require an extended warm-up period, however, so their usefulness in private cars remains limited.

UTC Fuel Cells (USA) is presently the leading manufacturer of commercial stationary fuel cell systems. Over 245 units of its 200kW PC25™ fuel cell power plant have been installed around the world since the system was launched in the early 1990s. PC25 systems provide clean, reliable power at a range of locations including a New York City police station, a major postal facility in Alaska and a science centre in Japan.

PAFCs have supplied stationary power for nearly 10 years. A model PC25 power plant from ONSI Corp. recently began supplying supplemental power in the new Conde Nast Building at 4 Times Square in New York City. During the next blackout in New York City, when this building remains lighted, it should provide some powerful publicity for fuel cells. Also in New York, the Yonkers Waste Treatment Plant has been powered by a 200 kw ONSI unit since 1997. This plant reforms sewage methane as a fuel, and the stacks have an estimated life of 5 to 6 years.

The military's interest in PAFCs led in 1993 to a program of purchasing these units for various bases where air quality is an issue. Between 1993 and 1997, 15 PAFCs from International Fuel Cells Corp. were placed in service through this program.

Molten Carbonate Fuel Cell History

Both molten carbonate and solid oxide fuel cells are high-temperature devices. As such, the technical history of both cells seems rooted in similar lines of research, with significant divergence appearing in the late 1950s.

In the 1930s, Emil Baur and H. Preis in Switzerland experimented with high-temperature, solid oxide electrolytes. They encountered problems with electrical conductivity and unwanted chemical reactions between the electrolytes and various gases (including carbon monoxide). The following decade, O. K. Davtyan of Russia explored this area further, but with little success. By the late 1950s, Dutch scientists G. H. J. Broers and J. A. A. Ketelaar began building on this previous work and decided that limitations on solid oxides at that time made short-term progress unlikely. They focused instead on electrolytes of fused (molten) carbonate salts.

By 1960, they reported making a cell that ran for six months using an electrolyte "mixture of lithium-, sodium- and / or potassium carbonate, impregnated in a porous sintered disk of magnesium oxide." However, they found that the molten electrolyte was slowly lost, partly through reactions with gasket materials. About the same time, Francis T. Bacon was working with a molten cell using two-layer electrodes on either side of a "free molten" electrolyte. At least two groups were working with semisolid or "paste" electrolytes and most groups were investigating "diffusion" electrodes rather than solid ones.

In the mid-1960s, the U.S. Army's Mobility Equipment Research and Development Center (MERDC) at Ft. Belvoir tested several molten carbonate cells made by Texas Instruments. These ranged in size from 100 watts to 1,000 watts output and were designed to run on "combat gasoline" using an external reformer to extract hydrogen. The Army especially wanted to use fuels already available, rather than a special fuel that might be difficult to supply to field units.

Solid Oxide Fuel Cell History

Both solid oxide and molten carbonate fuel cells are high temperature devices. The technical history of both cells seems to be rooted in similar lines of research until the late 1950s.

Swiss scientist Emil Baur and his colleague H. Preis experimented with solid oxide electrolytes in the late 1930s, using such materials as zirconium, yttrium, cerium, lanthanum, and tungsten. Their designs were not as electrically conductive as hoped and reportedly experienced unwanted chemical reactions between the electrolytes and various gases, including carbon monoxide.

In the 1940s, O. K. Davtyan of Russia added monazite sand to a mix of sodium carbonate, tungsten trioxide, and soda glass "in order to increase the conductivity and mechanical strength." Davtyan's designs, however, also experienced unwanted chemical reactions and short life ratings.

By the late 1950s, research into solid oxide technology began to accelerate at the Central Technical Institute in The Hague, Netherlands, Consolidation Coal Company, in Pennsylvania, and General Electric, in Schenectady, New York. A 1959 discussion of fuel cells noted that problems with solid electrolytes included relatively high internal electrical resistance, melting, and short-circuiting due to semi conductivity. It seems that many researchers began to believe that molten carbonate fuel cells showed more short-term promise.

Not all gave up on solid oxide, however. The promise of a high-temperature cell that would be tolerant of carbon monoxide and use a stable solid electrolyte continued to draw modest attention. Researchers at Westinghouse, for example, experimented with a cell using zirconium oxide and calcium oxide in 1962. More recently, climbing energy prices and advances in materials technology have reinvigorated work on SOFCs, and a recent report noted about 40 companies working on these fuel cells.

PEM Fuel Cell History

PEM technology was invented at General Electric in the early 1960s, through the work of Thomas Grubb and Leonard Niedrach. GE announced an initial success in mid-1960 when the company developed a small fuel cell for a program with the U.S. Navy's Bureau of Ships (Electronics Division) and the U.S. Army Signal Corps. The unit was fueled by hydrogen generated by mixing water and lithium hydride. This fuel mixture was contained in disposable canisters that could be easily supplied to personnel in the field. The cell was compact and portable, but its platinum catalysts were expensive.

PEM technology served as part of NASA's Project Gemini in the early days of the U.S. piloted space program. Batteries had provided spacecraft power in earlier Project Mercury missions, but the lunar flights envisioned for Project Apollo required a longer duration power source. Gemini's main objective was to test equipment and procedures for Apollo, and missions lasting up to 14 days included operational tests of fuel cells. GE's PEM cells were selected, but the model PB2 cell encountered repeated technical difficulties, including internal cell contamination and leakage of oxygen through the membrane. Geminis 1 through 4 flew with batteries instead.

GE redesigned their PEM cell, and the new model P3, despite malfunctions and poor performance on Gemini 5, served adequately for the remaining Gemini flights. Project Apollo mission planners; however, chose to use alkali fuel cells for both the command and lunar modules, as did designers of the Space Shuttle a decade later.

GE continued working on PEM cells and in the mid-1970s developed PEM water electrolysis technology for undersea life support, leading to the US Navy Oxygen Generating Plant. The British Royal Navy adopted this technology in early 1980s for their submarine fleet. Other groups also began looking at PEM cells. In the late 1980s and early 1990s, Los Alamos National Lab and Texas A&M University experimented with ways to reduce the amount of platinum required for PEM cells.

Recently PEM developers added the weatherproofing material Gore-Tex to their cells to strengthen the electrolyte.

Direct Methanol Fuel Cells (DMFC)

In recent years methanol fuel cell technology is developed. There have been significant activities in the United States to develop large- scale MCFC technology. Preliminary studies have been performed on large scale at Jet Propulsion Laboratory (1997) and at the los Alamos Laboratory (2000) and at the Penn state university. The micro direct methanol fuel cell is currently being aggressively pursued by several organization including Motorola, JPL, Toshiba, Hitachi etc. Last Update: Thursday 11 December 2008 Time: 23:43