Solid Oxide Fuel Cells

From Fundamental Principles to Complete Systems

Radenka Maric, Gholamreza Mirshekari

• Publisher: CRC Press
• Year: 2020
• Print ISBN: 9781466561168
• eBook ISBN: 9780429527845
• Topic: Physical Sciences
• Subtopic: Energy

Solid Oxide Fuel Cells: From Fundamental Principles to Complete Systems is a valuable resource for beginners, experienced researchers, and developers of solid oxide fuel cells (SOFCs). It provides a fundamental understanding of SOFCs by covering the present state-of-the-art as well as ongoing research and future challenges to be solved. It discusses current and future materials, and provides an overview of development activities with a more general system approach toward fuel cell plant technology, including plant design and economics, industrial data, and advances in technology.

• Provides an understanding of the operating principles of SOFCs
• Discusses state-of-the-art materials, technologies, and processes
• Includes a review of the current industry and lessons learned
• Offers a more general system approach toward fuel cell plant technology, including plant design and economics of SOFC manufacture
• Covers significant technical challenges that remain to be solved
• Presents the status of government activities, industry, and market

This book is aimed at electrochemists, batteries and fuel cell engineers, alternative energy scientists, and professionals in materials science.

1 Fundamental Aspects of Solid Oxide Fuel Cells

1.1 Background and Principles of SOFCs

Fuel cells have emerged as energy conversion devices that produce electrical power directly from electrochemical reactions by combination of gaseous fuel with an oxidant. Fuel cells have first successfully been used for space applications in the 1960s [2]. During the past decades, fuel cells have been developed and offered numerous advantages compared to conventional electrical power generation systems such as high-energy conversion efficiency, high power output, low noise, and zero environmental pollution, which have made them a promising technology for mobile and stationary power generation applications [1,2]. Today, fuel cells are widely utilized in spacecraft, automobiles, home power generation systems, etc.

Nowadays, there are different types of fuel cells classified by chemical characteristics of the electrolyte used, which in turn determines the operating temperature. Table 1.1 illustrates the technical characteristics of the main types of fuel cells that exist today. Fuel cells are categorized as alkaline fuel cell, direct methanol fuel cell, phosphoric acid fuel cell, solid acid fuel cell, proton exchange membrane fuel cell, molten carbonate fuel cell, solid oxide fuel cell (SOFC), and protonic ceramic fuel cell. The first five types have low to medium operating temperatures (50°C–210°C) with relatively lower electrical generation efficiencies (40%–55%). The other three types, however, operate at much higher temperatures (600°C–1000°C) with higher electrical generation efficiencies (45%–60%) [3]. Among the listed types of fuel cells, SOFCs are the most demanding for use as a power generation system from a materials point of view and due to their exceptional features such as:

• SOFCs offer high energy-conversion and electrical generation efficiencies (fuel input to electricity output).
• SOFCs have good fuel flexibility (e.g., natural gas and carbon-based fuels) and simplicity of design.
• Since SOFCs have a solid construction with no moving parts, they operate very quiet with minimal noise, and thereby, they can be installed indoors.
• The SOFCs’ high operating temperature leads to high-quality byproducts, and exhaust heat is used for co-generation and a variety of processes.
• Since precious metals are not used in SOFCs, the price is reasonable enough for high-volume manufacturing.
• The high efficiency and operating temperature of SOFCs result in low CO₂ emission.
• SOFCs do not need to work with corrosive liquid electrolyte, making them durable with a life expectancy of 40,000–80,000 h [1,3].

TABLE 1.1
Technical Characteristics of Different Fuel Cells

Types of Fuel Cell	Electrolyte	Operating Temperature (°C)	Fuel	Oxidant	Efficiency (%)
Alkaline fuel cell (AFC)	Potassium hydroxide	50–200	Pure hydrogen, or hydrazine	O2/Air	50–55
Direct methanol fuel cell (DMFC)	Polymer	60–200	Liquid methanol	O2/Air	40–55
Phosphoric acid fuel cell (PAFC)	Phosphoric acid	160–210	Hydrogen from hydrocarbons and alcohol	O2/Air	40–50
Sulfuric acid fuel cell (SAFC)	Sulfuric acid	80–90	Alcohol or impure hydrogen	O2/Air	40–50
Proton exchange membrane fuel cell (PEMFC)	Polymer, proton exchange membrane	50–80	Less pure hydrogen from hydrocarbons or methanol	O2/Air	40–50
Molten carbonate fuel cell (MCFC)	Molten salt (e.g. nitrate, sulfate, carbonate)	630–650	Hydrogen, carbon monoxide, natural gas, propane, marine diesel	CO2/O2/Air	50–60
Solid oxide fuel cell (SOFC)	Cera...

Table of contents

• Cover
• Half Title
• Series Page
• Title Page
• Copyright Page
• Table of Contents
• Preface
• Authors
• Chapter 1 Fundamental Aspects of Solid Oxide Fuel Cells
• Chapter 2 Materials: Electrolytes, Anodes, Cathodes, Interconnects, and Sealants
• Chapter 3 Processing
• Chapter 4 Cell and Stack Configuration
• Chapter 5 System Design and Optimization
• Chapter 6 Fuel Cell Technology Commercialization
• Chapter 7 Research, Demonstration, and Commercialization Activities in the US, Europe, and Asia
• Index