energy storage – apers

Fuel Cells vs. Batteries: What’s the Difference?

Razvan — Wed, 05 Jul 2023 01:56:33 +0000

As the world looks toward innovative technology to help reduce the carbon footprint, scarcity of resources has become a significant challenge.

With no single technology being enough to accommodate the green transition, we’re seeing massive investments in both fuel cell- and battery-related technologies. Some large-scale investments include new battery technologies for electric vehicles (EVs), wind turbines, trains, airplanes, commercial transport vehicles, and public infrastructure.

Currently, lithium-ion batteries make up about 70% of EV batteries and 90% of grid storage batteries. The marketplace is growing at a compound annual growth rate of 13.1%, projected to grow and reach $135 billion by 2031. The fuel cell market is growing rapidly, too, estimated to grow by 36% annually and reach $29 billion by 2028.

The differences between fuel cells and batteries are not always well understood. In this article, we will examine the differences and the role they will play in future innovations.

A Different Way to Generate and Store Electricity

Lithium-ion batteries and fuel cells produce electricity through chemical reactions that are very similar. However, the source of energy used for the chemical reaction is different. In simple terms, batteries produce electricity using stored energy while fuel cells generate power with hydrogen-rich fuel.

Lithium-ion batteries contain anodes and cathodes and an electrolyte separator that fills the remaining spaces. Both anodes and cathodes can store lithium ions. Energy is produced and stored as the lithium ions travel between the electrodes through the electrolyte.

Unlike batteries, fuel cells do not store chemical energy in their components. Instead, they generate energy by converting the potential energy stored in hydrogen or other hydrogen-rich fuels such as methanol, ammonia, and ethanol.

Much like batteries, when fuel cells are connected to an electrical circuit, hydrogen ions move from the cathode to the anode, converting chemical energy into electrical energy.

Materials for Batteries Are Scarce; Materials for Fuel Cells Are Not

Lithium-ion batteries are built using materials that are in short supply such as lithium, nickel, and cobalt. Although production of these materials is increasing by more than 25% per year, there simply aren’t enough minerals available on the planet to meet the demand.

A $2.4-billion lithium project set for Serbia was shut down in 2022 due to environmental mining concerns, which some experts say is likely to prolong the shortage for years to come.

As a result, several countries (and companies) are trying to gain control of the resources required to build batteries. Inevitably, others are left without the possibility to build them.

At the same time, shortages result in higher prices. Countries that have to import these scarce metals cannot control production or pricing. That’s a major reason why India is trying to move away from lithium-ion battery technology and toward fuel cells.

Others are trying to develop batteries that rely less on scarce resources. For example, LiFePO4 batteries (Lithium Iron Phosphate) use lithium but do not require nickel or cobalt. Researchers are also attempting to build other types of batteries with even more common materials, but they have yet to yield acceptable performance levels.

Fuel cells are less complicated in terms of resources. They use common materials like aluminum and stainless steel in their construction. Their fuel, hydrogen, is also the most abundant chemical element in the universe.

Batteries Are More Energy-Efficient than Fuel Cells

No energy source is 100% efficient. Some energy is lost when it is transformed into other forms of energy. Energy can be lost in multiple forms such as heat, light, sound, or magnetic loss. The goal is to reduce the amount of lost energy to improve efficiency.

EV powertrains using batteries or fuel cells are significantly more energy efficient than gas-powered engines, which can lose as much as 80% of their energy through engine heat, evaporation, oil extraction, refinement, and transport. However, batteries and fuel cells are not immune. Energy loss can occur during storage, charging, and discharging.

Batteries suffer significantly lower energy losses than fuel cells. Batteries can reuse between 80–90% of the chemical energy stored. Some of the energy lost to heat can be reused for other purposes, such as to provide heat in an EV’s cabin or even to warm up passenger meals in airplanes.

Reusing the energy lost as heat is called cogeneration. EV manufacturers efficiently use this method to reduce battery drain. By heating the cabin with energy lost from heat, they can avoid draining down the battery power.

Fuel cells, by comparison, generally transform 40% to 60% of their energy to produce electrical power. Using cogeneration from waste heat can theoretically improve fuel cell energy efficiency to as high as 85%.

In cold weather, fuel cells can be almost as efficient as batteries. This is because EV batteries use up to 40% of the electrical energy for heating.

Shorter Charging Times for Fuel Cells

One frustration for EV owners is the time it takes to charge their vehicles. Charging an electric battery takes time. For regular EV batteries, a full charge can take between 45 minutes and 2 hours. In the best-case scenarios, fast charging takes between 20-25 minutes.

To achieve fast charging times, batteries must be maintained within very specific temperature tolerances. They may need to be cooled down, as the current going into the battery produces excess heat. They may also need to be heated up in colder locations, as batteries cannot be charged below 0C.

While larger batteries can be charged at a higher power (i.e., more kW) than smaller batteries, their charging time is typically much longer. For commercial vehicles like delivery trucks, buses, trains, and airplanes, charging times have become a lot longer because charging stations have not yet been adapted for larger batteries.

For example, many EV buses require four to five hours to charge, a time that is impractical in many situations. The time required to charge commercial vehicles could be drastically reduced, but we need to develop specialized stations capable of charging at a much higher power (i.e., in terms of megawatts). Tesla, for example, recently announced a charging station capable of charging at more than 1 MW.

Filling up a fuel-cell vehicle is much faster than charging up an electric vehicle. Fuel cell tanks are filled up with hydrogen-rich fuels, much like gas-powered cars are filled up with gasoline. It can be done in just a few minutes. This makes fuel cells very attractive for commercial vehicle applications, as it reduces charging times to practical levels.

Different Environmental Impact

Fuel cells and batteries are part of the solution for a greener future, but it doesn’t mean they have no environmental impact. They simply replace technologies that are way more polluting.

Fuel cells need hydrogen-rich fuel, and how that fuel is produced matters. A color classification system was developed to understand the origin and environmental impact of hydrogen. For example:

Green hydrogen is produced from renewable energy sources like wind power.
Blue hydrogen is produced from natural gas and heated water.
Black hydrogen is produced using coal.

If the hydrogen that we produce comes from polluting energy sources, our efforts are counterproductive.

Similarly, the electrical power used to charge batteries can also come from different sources like wind power, hydropower, and coal and can also impact the environment.

Extracting the rare metals used in batteries also has an impact. Lithium mines need impressive quantities of water and occupy large areas. As an example, lithium mines in Chile using evaporation ponds require 21 million liters of water per day. These installations require about 2.2 million liters of water to produce a ton of lithium.

Nickel dust can also contaminate the air we breathe if industries are not subjected to strict environmental regulations. In Canada, the government eased air quality regulations for nickel production hoping to make it more attractive to battery manufacturers, but it stirred up debates on the battery manufacturing industry and its impact on public health.

LiFePO4 batteries, better known as LFP (lithium-iron phosphate), are a type of lithium-ion battery that uses iron instead of cobalt and nickel. Consequently, they have a lower environmental impact than other types of lithium-ion batteries.

In the end, all technologies can have a negative environmental impact. The electrification of our industries alone is not enough. The entire battery and fuel cell supply chain need to be monitored and regulated if our goal is to mitigate the environmental impact.

More Serious Safety Issues with Fuel Cells

As the world continues to create and adopt innovative technologies, we also need to understand the new issues that may result and continue to update how we manage safety.

Lithium-ion batteries and fuel cells are not without danger. Fuel cells use hydrogen and hydrogen-rich fuels, which are highly flammable and explosive. Hydrogen is stored as a gas or a cryogenic liquid in pressurized tanks. If a crash happens with a hydrogen-powered car, there can be a massive explosion.

The Toyota Mirai stores hydrogen gas in two separate tanks, compressed at a pressure of 10,000 pounds per square inch (psi). While the tanks are carbon fiber reinforced to withstand extremely violent impacts, the potential for explosion is still there, which is why some say driving around with hydrogen-filled tanks may not be the safest idea.

With lithium-ion batteries, fires can be very difficult to extinguish due to what is called a thermal runaway. Still, there is no explosion, allowing passengers time to get out of the vehicle. This is because batteries are designed to slow down failures, making them happen progressively. They often simply begin with a smell or fumes. After several seconds, minutes or even hours, failures turn into a chain reaction that goes from cell to cell.

Conclusion

Fuel cells and batteries both have significant potential for the future. Innovation can improve safety and reduce environmental impacts even further.

Batteries are the more mature solution, having been around for more than two hundred years. However, we may have already reached what’s close to peak energy density with batteries. Fuel cells are a less mature technology but may offer a storage solution for applications that require a higher range.

Today, different sectors of the automotive industry are taking different directions for their electrification. Lithium-ion batteries have become the solution of choice for most automotive applications, while fuel cells are preferred for commercial vehicles like buses, trains, trucks, and airplanes. Countries that have little control over battery production also seem to be moving toward fuel cells.

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New Battery Tech Could Extend EV Range 10x or More

Razvan — Mon, 10 Apr 2023 10:07:43 +0000

While the electric vehicle market expands, some drivers remain hesitant to switch to a fuel-free car or truck because of range anxiety, or the fear that the battery of their EV won’t have enough power to get to another charging station. But researchers have found a way that could give EV batteries a pretty substantial boost, extending the vehicle range more than 10 times.

Researchers from Pohang University of Science & Technology (POSTECH) and Sogang University collaborated on a study, which they published in the journal Advanced Functional Materials. The team developed a polymeric binder for a stable, reliable, high-capacity anode material rather than conventional anodes made of graphite or other materials.

Typically, swapping conventional anodes for high-capacity anode materials, like silicon, can expand while reacting with lithium, and this volume expansion can limit the battery’s performance. To confront this challenge, the team worked with charged polymer binders to minimize volume expansion.

“The research holds the potential to significantly increase the energy density of lithium-ion batteries through the incorporation of high-capacity anode materials, thereby extending the driving range of electric vehicles,” Soojin Park, professor for the Department of Chemistry at POSTECH, said in a statement. “Silicon-based anode materials could potentially increase driving range at least tenfold.”

Existing research has used chemical crosslinking to create covalent bonding between binder molecules as well as hydrogen bonding. Bonds formed in chemical crosslinking cannot be reversed once broken, which has been a challenge in creating more reliable batteries. Then, the issue with hydrogen bonding is that it is not as strong.

So, the researchers developed a polymer to take the benefits of hydrogen bonding, namely that the bonds can be broken and restored, and paired them with Coulomb force, meaning the force of attraction between unlike charges (positive and negative) creates a stronger bond. The result? A layered polymer with alternating positive and negative charges that has strong, reversible bonds to better control volume expansion, giving potential to create stronger, more reliable EV batteries.

While EV range anxiety is a common concern for drivers, especially considering the general need for more charging infrastructure, previous studies have found that EV batteries typically provide more than enough range for most people, from everyday commuters to weekend roadtrippers. One recent study found that up to 37% of drivers could meet their regular driving needs in EVs with smaller batteries and ranges, but even those who want to travel farther distances can get where they need to go just fine on EVs with larger batteries.

Today, many drivers can ride an EV for about 250 miles before needing to recharge, while most drivers only travel up to 30 miles per day. According to EverCharge, many gas cars have a range of about 250 to 300 miles. With ongoing innovations and research into EV batteries, range anxiety could soon be a thing of the past, with EVs that could have better ranges than conventional vehicles.

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Energy storage technologies: meeting the demands of the 21st century

Althaus — Fri, 24 Mar 2023 11:47:40 +0000

The global energy landscape is changing rapidly, driven by the need to reduce carbon emissions and the transition to a sustainable energy future. As a result, energy storage technologies are becoming an important solution for managing and storing energy generated from renewable sources. In this article, we explore the different types of energy storage technologies, their applications and the benefits they offer.

Energy storage technologies are key to managing and storing energy from renewable sources such as solar and wind. They allow excess energy to be stored for use during periods of peak demand, thereby reducing the need for electricity from the grid and improving its stability. Energy storage technologies also offer numerous other benefits, including cost savings, increased reliability and reduced environmental impact.

Storage in batteries

Battery storage is one of the most widely used energy storage technologies. It uses rechargeable batteries to store electricity that can be used during periods of high demand. Battery storage can be used in a variety of applications including residential, commercial and industrial. Lithium-ion batteries are the most commonly used battery type in energy storage systems, although other battery types such as lead acid and flow batteries are also used.

An example of the use of battery storage is South Australia’s Tesla battery, the world’s largest lithium-ion battery. The battery has a capacity of 100 megawatts and can power 30,000 homes for one hour during a power outage. The battery was installed in response to a national blackout in 2016 and has since helped stabilize the power grid during periods of high demand.

Pumping stations with hydroelectric storage

Storage pumping is a form of energy storage in which water is pumped from a lower reservoir to an upper reservoir when electricity is plentiful, and the water is then released to generate electricity when needed. Pumped storage is an established technology that has been used since the 1920s. It is a highly efficient form of energy storage, with efficiencies of up to 80%.

An example of pumped storage in action is the Bath County Pumped Storage station in Virginia, the largest such facility in the world. The plant has a capacity of 3,003 megawatts and can power 3 million homes for up to 10 hours.

Flywheel storage

Flywheel energy storage is a kinetic energy storage technology that involves spinning a rotor at high speeds to store energy. Energy is stored as rotational kinetic energy in the rotor, and when necessary, the rotor is slowed down and the kinetic energy is converted back into electrical energy.

Flywheel storage systems typically consist of a rotor, motor/generator and vacuum encapsulation to reduce air resistance and friction. The rotor can spin at speeds of up to 60,000 revolutions per minute and can store energy for short periods of time, usually from a few seconds to a few minutes.

Flywheel energy storage systems are highly efficient, with efficiencies of up to 90%, and have a long life of up to 20 years. They are particularly suitable for applications where high power is required for short periods of time, such as providing frequency regulation services to the grid or providing backup power for data centres. Flywheel energy storage is also environmentally friendly as it produces no emissions and requires no toxic materials.

Thermal energy storage

Thermal storage is a form of energy storage in which heat or cold is stored for later use. Thermal storage can be used for a range of applications, including heating and cooling buildings and generating electricity. Various technologies can be used for thermal storage, such as phase change materials, which store energy by changing their physical state, and thermal storage tanks, which store hot or cold water.

One example of thermal storage in action is the Drake Landing solar community in Alberta, Canada. The community uses a district heating system with 800 solar panels and 52 thermal storage tanks to provide heat to homes. The system can meet 97% of the community’s space heating needs with renewable energy.

Conclusions

Energy storage technologies are becoming increasingly important in the transition to a sustainable energy future. They offer numerous benefits, including improved network stability, cost savings and reduced environmental impact. As renewable energy sources become more widespread, energy storage technologies will become even more important.

Battery storage is one of the most widely used energy storage technologies and is suitable for a wide range of applications including residential, commercial and industrial. Pumped storage power plants are an established technology that is highly efficient and can provide electricity to millions of homes. Flying storage is a newer technology that is very efficient and can help stabilise the power grid during periods of high demand. Thermal storage can be used for a wide range of applications, including heating and cooling of buildings and power generation.

As the world continues to move towards a sustainable energy future, it is essential that we continue to invest in and develop energy storage technologies. By doing so, we can ensure that we have a reliable, resilient and sustainable energy system that can meet the needs of the 21st century and beyond.