Fuel Cell and Lithium-ion Capacitor (LIC)

What is a Fuel Cell

A fuel cell is a technology that generates electricity and heat through a chemical reaction of hydrogen and oxygen (reverse reaction of water electrolysis).

First, since fuel cells use hydrogen as fuel, they emit almost no carbon dioxide or nitrogen oxides from combustion. Therefore, it is attracting attention as an environmentally friendly energy source.

Advantages of Fuel Cells

Fuel cells have high power generation and good fuel efficiency, so using fuel cell vehicles makes it possible to use energy more efficiently. In addition, fuel cell vehicles have the advantage of shorter refueling times and longer driving distances than electric vehicles.

Fuel cells are also highly versatile as an energy supply source and may be used in various fields, such as construction machinery, power plants, ships, and railways.

In addition, fuel cells help load-balance the power grid as demand increases. Fuel cell power generation systems can be combined with renewable energy sources such as solar and wind power and can supply power appropriately according to demand.

Thus, fuel cells are attracting more and more attention as a solution to environmental and energy problems. Further research and the spread of fuel cells are expected to lead to realizing a more sustainable society.

Challenges of Fuel Cells

On the other hand, fuel cells have some issues. Among them, I will briefly explain the disadvantages of deterioration due to output fluctuations and the inability to use energy regeneration.

Degradation due to Output Fluctuation

First, fuel cells use hydrogen as fuel, so if the hydrogen supply is unstable, the output will be unstable. This is a problem as it can affect the performance and life of the fuel cell.

Fuel cells may also fluctuate in power output. For example, fuel cell vehicles require a lot of power when accelerating or going uphill, so the power output fluctuates. Such output fluctuations can shorten the life of the fuel cell.

Energy Regeneration

Furthermore, fuel cells have the disadvantage of not being able to store regenerated energy.

Energy regeneration is the recovery of energy generated by applying the brakes, etc., and converting it into electric power for reuse. However, fuel cell vehicles cannot recover the energy generated when the brakes are applied, so energy utilization efficiency may decrease.

TheHhybrid System of Lithium-ion Capacitor (LIC) and Fuel Cell

In order to solve these problems, research and development of various technologies are progressing. For example, hybrid systems that combine fuel cells and lithium-ion capacitors are being developed to suppress power output fluctuations and enable energy regeneration.

What is a Lithium-ion Capacitor (LIC)?

A Lithium-ion Capacitor uses a carbon-based material that can absorb lithium ions as a negative electrode material while using the principle of a general electric double-layer capacitor and adding lithium ions to improve the energy density. It's a capacitor.

Lithium-ion capacitors are characterized by their long life, high safety, and high input/output performance. Unlike fuel cells, they can utilize energy regeneration.

What is a Hybrid System?

Taking advantage of the characteristics of two different energy storages, a hybrid system that combines a fuel cell and a Lithium-ion Capacitor is developed.

By utilizing the characteristics of the Lithium-ion Capacitor's responsiveness to load fluctuations, deterioration due to load fluctuations in the fuel cell can be suppressed, and as a result, the service life of the fuel cell can be extended.

For applications that require an instantaneous response to output fluctuations during self-sustained operation, the high input/output characteristics of the LIC make it possible to instantly discharge large currents, improving the convenience of power generators.

Also, by utilizing the regeneration of the Lithium-ion Capacitor, it is possible to improve the energy efficiency of the entire system while increasing the output.

When it comes to hybrid systems with fuel cells, people tend to think of lithium-ion batteries, but hybrid systems with Lithium-ion Capacitors can reduce the weight and size of the entire system itself and are said to have a long life and high safety.

Some real-life use cases of this system are fuel cell vehicles or fuel cell forklifts, and fuel cell power generators.

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