United States phosphoric acid fuel cell development

Development History Phosphoric acid fuel cells were developed from the 1970s through the 1990s by several companies in the United States, including ONSI, a division of International Fuel Cells (IFC), which eventually became United Technologies Corporation... 

As mentioned earlier, two types of fuel cell have been developed beyond the prototype stage. These are the alkaline (KOH) electrolyte hydrogen-oxygen cell and the phosphoric acid and electrolyte hydrogen-air fuel cell. Both of these developments took place in the United States. 

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