Fuel cells are essential in the transition to electric vehicles.
Fuel cells are electrochemistry -based devices that generate electricity through a chemical reaction, usually between hydrogen and oxygen, without combustion. In a fuel cell, hydrogen is oxidized at the anode and oxygen is reduced at the cathode, producing water, heat and electricity as byproducts. This process is efficient and emits only water as waste, which is why it is considered a clean and sustainable technology for energy generation.
Types of fuel cells
Fuel cells are classified into several types depending on the type of electrolyte they use and the operating temperature. The most common ones are described below.
Proton exchange membrane fuel cells (PEMFC)
Also known as polymer fuel cells, they use a solid polymer membrane as the electrolyte. They operate at low temperatures (around 80°C) and are ideal for applications in vehicles and portable devices due to their fast response and high efficiency. However, they require pure hydrogen as fuel , which can complicate their use.
Solid Oxide Fuel Cells (SOFC)
They use a solid ceramic electrolyte that conducts oxygen ions at very high temperatures (500-1,000 °C). They are efficient and can run on a variety of fuels, including hydrogen and natural gas. Its application is mainly in stationary power generation due to the high temperatures necessary for its operation.
Phosphoric acid fuel cells (PAFC)
They use phosphoric acid as an electrolyte and operate at intermediate temperatures (around 200 °C). They are robust and are used in stationary power systems, such as in hospitals and large buildings, where efficiency and reliability are crucial.
Alkaline fuel cells (AFC)
They use an alkaline electrolyte, such as potassium hydroxide, and operate at low temperatures. They are known for their high efficiency in space applications, such as those used in the Apollo program. However, they are very sensitive to carbon dioxide pollution, which limits their use to specific applications.
Direct Methanol Fuel Cells (DMFC)
They use liquid methanol as fuel, which is directly converted into electricity instead of hydrogen. They operate at low temperatures (around 60-120 °C) and use a proton exchange membrane similar to that of PEMFCs. DMFCs are ideal for portable devices and applications where hydrogen storage is complicated. Although they are less efficient than other types of fuel cells, their ease of handling and the availability of methanol make them suitable for specific applications, such as portable chargers and small power systems.
Electrolyte, anode and cathode
Electrolyte is a substance that conducts electricity by allowing the movement of ions within it. In fuel cells, it facilitates the flow of ions between the anode and cathode , which is essential for electricity generation.
The anode (sometimes written without an accent, anode ) is the electrode where oxidation occurs, that is, the chemical reaction in which electrons are lost. In fuel cells, the anode is where the hydrogen or fuel is broken down into protons and electrons.
The cathode is the electrode where the redox reaction occurs, that is, the chemical reaction in which electrons are gained. In a fuel cell, the cathode is where oxygen reacts with electrons and protons to form water.
Various electronic devices can be charged with fuel cells.
Related technologies
Fuel cells are closely related to several technologies that allow their efficient and sustainable operation.
Hydrogen production
Hydrogen can be produced from various sources, such as natural gas reforming, biomass gasification, and through water electrolysis. Its clean production, using renewable sources such as solar or wind energy, is key to reducing the environmental impact of this technology.
Hydrogen storage
Safe and efficient storage of hydrogen is a technological challenge. It can be stored in gaseous form at high pressure, as a liquid at low temperatures, or by absorption into solid materials. Advances in materials such as metal hydrides and compression technologies are improving their viability for mobile and stationary applications.
Water electrolysis
A process that uses electricity to break down water into hydrogen and oxygen. When electricity from renewable sources is used, electrolysis makes it possible to produce hydrogen in a sustainable way. This green hydrogen is essential for a clean energy transition.
A sustainable energy future
The integration of renewable energies into global energy systems is essential to achieve energy autonomy and reduce dependence on fossil fuels. To achieve this, education in renewable energy is crucial, fostering environmental awareness and preparing new generations to face energy challenges. Adopting alternative fuels , such as cleanly produced hydrogen, is a key step towards sustainability .
Environmental legislation plays a vital role in driving policies that support these transitions, promoting investment in research and development. This comprehensive approach ensures that progress towards a sustainable energy system is not only technological, but also socially conscious and regulated for the common good.
The low level of emissions from fuel cells makes them essential against global warming.
The fight against global warming
Fuel cells are positioned as one of the most promising low-emission technologies in the fight against global warming. By producing clean energy from hydrogen , they generate electricity and water as byproducts, making them a zero-emission energy source. Unlike traditional sources, fuel cells do not emit greenhouse gases or contribute to carbon emissions, key factors in accelerating climate change.
In this context, energy policies and emissions regulations are increasingly focusing on incentivizing the development and adoption of these technologies. International climate agreements, such as the Paris Agreement (signed in 2015 by 196 countries, with the goal of limiting global temperature rise to less than 2 degrees Celsius above pre-industrial levels), underscore the importance of reducing emissions and promote the transition to clean energy. Fuel cells play a crucial role in meeting these goals, supporting the global effort to mitigate the effects of global warming and protect the environment.