How do alkaline fuel cells work?

Alkaline fuel cells (AFCs) generate electricity through a chemical reaction between hydrogen and oxygen, using an alkaline electrolyte.

The Basics of Alkaline Fuel Cell Operation

AFCs operate through the following process:

Electrolyte: AFCs traditionally use a solution of potassium hydroxide (KOH) in water as the electrolyte. Novel AFCs are being developed that use a polymer membrane as the electrolyte.
Electrodes: The cell consists of an anode (negative electrode) and a cathode (positive electrode). According to the reference, AFCs can use a variety of non-precious metals as a catalyst at the anode and cathode.
Fuel and Oxidant: Hydrogen (H₂) is supplied to the anode, and oxygen (O₂) is supplied to the cathode.
Electrochemical Reactions:
- At the Anode: Hydrogen reacts with hydroxide ions (OH^-) from the electrolyte to produce water (H₂O) and electrons (e^-):
  
  H₂ + 2OH^- → 2H₂O + 2e^-
- At the Cathode: Oxygen reacts with water and electrons to produce hydroxide ions:
  
  O₂ + 2H₂O + 4e^- → 4OH^-
Electron Flow: The electrons generated at the anode flow through an external circuit, creating an electric current. This current is what powers external devices.
Ion Transport: Hydroxide ions (OH^-) migrate through the electrolyte from the cathode back to the anode, completing the circuit.

High Efficiency: AFCs are known for their high electrical efficiency.
Non-precious Metal Catalysts: AFCs use a variety of non-precious metals as catalysts at the anode and cathode.
Reduced Costs: the possibility to use non-precious metals as catalysts leads to reduced costs.

Component	Function
Anode	Site of hydrogen oxidation
Cathode	Site of oxygen reduction
Electrolyte	Conducts hydroxide ions (OH^-) between electrodes
External Circuit	Allows electrons to flow, creating electrical current to power load