Comparison between Acidic and Alkaline

Six types of fuel cells have evolved in the past decades. They are called after their electrolyte, the substance that transports the ions. The electrolyte dictates the operating temperature of a fuel cell type. Depending on the operating temperature, a specific catalyst is chosen to oxidize the fuel. Fuel cell types therefore all have different catalysts. A brief summary of these six fuel cell types is given below.

Fuel Cell TypeCommon ElectrolyteOperating
System OutputElectrical EfficiencyApplications
Polymer Electrolyte Membrane (PEM)Solid organic polymer poly-perfluorosulfonic acid50 – 100°C
122 – 212°F
<1kW – 250kW60% (direct)
25-40% (reformed)
Backup power
Portable power
Small distributed generation
Direct Methanol   (DMFC)Solid organic polymer poly-perfluorosulfonic acid50 – 100°C
122 – 212°F
Up to 1.5kW20 – 25%Consumer goods   Laptops Mobile phones
Alkaline (AFC)Aqueous solution of potassium hydroxide soaked in a matrix90 – 100°C
194 – 212°F
10kW – 100kW60%Military
Phosphoric Acid (PAFC)Liquid phosphoric acid soaked in a matrix150 – 200°C
302 – 392°F
50kW – 1MW
(250kW module typical)
32-38%Distributed generation
Molten Carbonate (MCFC)Liquid solution of lithium, sodium, and/or potassium carbonates soaked in a matrix600 – 700°C
1112 – 1292°F
<1kW – 1MW
(250kW module typical)
45-47%Electric utility
Large distributed generation
Solid Oxide (SOFC)Solid zirconium oxide to which a small amount of Yttria is added650 – 1000°C
1202 – 1832°F
5kW – 3MW35-43%Auxiliary power
Electric utility
Large distributed generation
System Efficiency
Electrolysis and The Fuel Cell Process

Get industry recognized certification – Contact us