What are batteries, fuel cells, and supercapacitors?

Electrochemical energy production is drawing interest as an alternative energy/power source. Critical to the success of this source is for the design to be more sustainable and more environmental friendly. Systems for electrochemical energy storage and conversion include batteries, fuel cells, and electrochemical capacitors (ECs). All are based on the fundamentals of electrochemical thermodynamics and kinetics. All three are needed to service the wide energy requirements of various devices and systems.