Alkaline FC

Overview

Alkaline Fuel Cells (AFCs) are a type of fuel cell that uses an alkaline electrolyte, typically potassium hydroxide ( KOH), to convert the chemical energy of hydrogen and oxygen into electrical energy. AFCs are known for their high efficiency and ability to operate at relatively low temperatures, making them suitable for various applications, including space missions and stationary power generation.

Diagram of an alkaline fuel cell

Process Description

1. Hydrogen Supply: Hydrogen gas (H₂) is supplied to the anode side of the fuel cell.
2. Electrochemical Reaction: The AFC operates at low to moderate temperatures (typically 60-100°C). The alkaline electrolyte allows hydroxide ions (OH^-) to migrate from the cathode to the anode.
   • At the Anode: Hydrogen molecules are split into protons and electrons.
     • H₂ + 2OH^- → 2H₂O + 2e^-
   • At the Cathode: Oxygen molecules react with water and electrons to form hydroxide ions.
     • O₂ + 2H₂O + 4e^- → 4OH^-
3. Electricity Generation: The movement of electrons through an external circuit generates electricity.
4. Water Production: Water is produced as a byproduct at the anode.

Benefits

• High Efficiency: AFCs can achieve high electrical efficiencies, typically around 60% to 70%.
• Rapid Start-Up: Capable of starting up quickly, making them suitable for applications requiring immediate power.
• Operates at Low Temperatures: Compared to other fuel cells, AFCs operate at lower temperatures, reducing material stress and simplifying system design.
• Proven Technology: Successfully used in various applications, including NASA's Apollo missions and the Space Shuttle program.

Applications

• Stationary Power Generation: Suitable for small to medium-scale power generation applications.
• Backup Power: Provides emergency power for critical infrastructure.
• Portable Power: Used in portable power units for field operations and remote locations.

Challenges

• CO₂ Sensitivity: AFCs are sensitive to CO₂, which can form carbonates in the electrolyte, reducing performance and lifespan.
• Electrolyte Management: Requires careful management of the alkaline electrolyte to prevent leakage and degradation.
• Material Durability: The alkaline environment can be corrosive to certain materials, necessitating the use of corrosion-resistant components.
• Fuel Purity: Requires high-purity hydrogen to avoid contamination and ensure optimal performance.

Future Outlook

Advancements in materials and electrolyte management are expected to enhance the durability and performance of AFCs. Efforts to develop CO₂-resistant electrolyte formulations and improved system designs will address current challenges, making AFCs more viable for a broader range of applications.

ES Model Parameters

All the parameters concerning the Alkaline FC are listed in the table below.

entry_key	value	unit	sets	source_reference
ELECTRICITY_LV (layer)	2.915	kWh	CAN	Slaymaker, Amara, (2021): "Demographic and Geographic Region Definition in Energy System Modelling. A Case Study of Canada's Path to Net Zero Greenhouse Gas Emissions by 2050 and the Role of Hydrogen"
H2_HP (layer)	-4.255	kWh	CAN	Slaymaker, Amara, (2021): "Demographic and Geographic Region Definition in Energy System Modelling. A Case Study of Canada's Path to Net Zero Greenhouse Gas Emissions by 2050 and the Role of Hydrogen"
HEAT_LOW_T_DECEN (layer)	1	kWh	CAN	Slaymaker, Amara, (2021): "Demographic and Geographic Region Definition in Energy System Modelling. A Case Study of Canada's Path to Net Zero Greenhouse Gas Emissions by 2050 and the Role of Hydrogen"
c_inv	376.57	CAD/kW	CAN	Slaymaker, Amara, (2021): "Demographic and Geographic Region Definition in Energy System Modelling. A Case Study of Canada's Path to Net Zero Greenhouse Gas Emissions by 2050 and the Role of Hydrogen"
c_maint	7.53	CAD/kW/y	CAN	Slaymaker, Amara, (2021): "Demographic and Geographic Region Definition in Energy System Modelling. A Case Study of Canada's Path to Net Zero Greenhouse Gas Emissions by 2050 and the Role of Hydrogen"
c_p	0.97	-	CAN	Slaymaker, Amara, (2021): "Demographic and Geographic Region Definition in Energy System Modelling. A Case Study of Canada's Path to Net Zero Greenhouse Gas Emissions by 2050 and the Role of Hydrogen"
lifetime	35	y	CAN	Slaymaker, Amara, (2021): "Demographic and Geographic Region Definition in Energy System Modelling. A Case Study of Canada's Path to Net Zero Greenhouse Gas Emissions by 2050 and the Role of Hydrogen"

References

Data Sources
Slaymaker, Amara. (2021). "Demographic and Geographic Region Definition in Energy System Modelling. A Case Study of Canada's Path to Net Zero Greenhouse Gas Emissions by 2050 and the Role of Hydrogen"