History of the PEMFC

A first version of polymer electrolyte membrane fuel cells, which had a power of 1 kW, was built in the early 1960s by the General Electric for the Gemini spacecraft. 

Electrochemical Power Sources Batteries, Fuel Cells, and Supercapacitors, First Edition. Vladimir S. Bagotsky, Alexander M. Skundin, and Yurij M. Volfkovich 2015 John Wiley Sons, Inc. Published 2015 by John Wiley Sons, Inc. 

PROTON-EXCHANGE MEMBRANE FUEL CELLS (PEMFC) 

A sul fated polystyrene ion-exchange membrane was used as the electrolyte in these fuel cells. The electrodes contained about 4 mg/cm of a platinum catalyst. Because of the marked ohmic resistance of the membrane, the current density was below 100 mA/cm, with a voltage of about 0.6 V for an individual cell. This corresponds to a specific power of the fuel cell of about 60 mW/cm. Because of the insufficient chemical stability of the membrane used, the total lifetime of the battery was below 2000 h. The high cost of such a battery excluded uses in fields other than space flight. 

Basically a combination of three factors was responsible for this important progress  

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