Understand hydrogen fuel cells in 3 minutes! Why are they the future of new energy vehicles?

As humans got used to using fire to bring convenience to their daily lives, the fossil energy that had existed on the earth for billions of years gradually began to be consumed.

As far as the automobile industry is concerned, at the end of 2019, the domestic car ownership reached 260 million, and the consumption of various types of fuels was incalculable, resulting in increasingly severe environmental problems and the risk of energy shortages.

As the "main force" of fossil energy consumption, the booming automobile industry is one of the important factors. With the user's demand for less pollutants and less noise, electric vehicles have become the focus of consideration. So should it be lithium iron phosphate or ternary lithium battery? Each has its own advantages and disadvantages. However, some governments and companies with a longer-term vision are also committed to the research and development of hydrogen fuel cell electric vehicles. As a contemporary young person who may see the mass production of hydrogen energy vehicles, it is very necessary to understand them.

1. Working principle of hydrogen engine

Although the method of generating electricity is different, hydrogen energy will eventually be converted into electricity to drive the vehicle.

As the car is driving, a process called reverse electrolysis actually occurs, in which hydrogen reacts with oxygen in the fuel cell. The hydrogen comes from one or more gas tanks built into the FCEV, while the oxygen comes from the surrounding air. The end products of this reaction are only electricity, heat and water, which are emitted through the exhaust in the form of water vapor. Therefore, hydrogen-powered vehicles are zero-emission locally and can reach zero emissions within one minute.

The electricity generated in the fuel cell of a hydrogen engine can take two routes depending on the needs of the specific driving situation. It either flows to the electric motor and directly powers the FCEV, or it charges the battery, which stores energy until the engine needs it. This battery is called a traction battery and is much smaller than the battery of a full electric vehicle, and therefore weighs less, because it is constantly being charged by the fuel cell.

Like other electric cars, hydrogen cars can also recover or "recharge" braking energy. The electric motor converts the car's kinetic energy back into electricity and feeds it into a backup battery.

What makes hydrogen cars different from other electric cars is that they can generate their own electricity. Therefore, unlike pure electric or plug-in hybrid cars, they cannot be charged from an external power source and can only be powered by built-in batteries. Therefore, hydrogen cars actually have their own highly efficient power plant: fuel cells.

2. The biggest advantages and disadvantages of hydrogen vehicles

The most important thing for a new technology to develop and continue is whether its market value can be widely recognized by users. As for hydrogen-powered vehicles, there are at least four benefits for users:

⑴The propulsion of hydrogen fuel cell vehicles is purely electric. When you drive, it feels like driving a normal electric car. What does this mean? Since the electric motor can provide full torque even at low speeds, there is almost no engine noise and no starting feeling.

⑵ Another advantage is the short charging time. Depending on the charging station and battery capacity, a fully electric car currently takes 30 minutes to several hours to fully charge. On the other hand, a fuel cell car's hydrogen tank is full and can be used again in less than five minutes. For users, this brings the vehicle's usability and flexibility in line with that of conventional cars.

⑶At present, hydrogen cars still have a longer driving range than pure electric cars. A full tank of hydrogen will last about 300 miles (about 480 kilometers). Battery-powered cars can match this with very large batteries, which in turn will lead to an increase in vehicle weight and charging time.

⑷ The driving range of a fuel cell vehicle is independent of the outside temperature. In other words, it does not deteriorate in cold weather.

Interestingly, the biggest drawback of hydrogen vehicles is also based on the market and user choice. Simply put, the scarcity of hydrogen fuel filling stations puts users in a state of low demand. Without widespread market demand, it is difficult for hydrogen fuel cell vehicles to be mass-produced in the market and profitable. It will also lead to excessively high prices for single vehicles, which are difficult for ordinary users to afford, further exacerbating the suppression of demand. Therefore, only after the government leads the construction of such infrastructure and is fruitful, can the mass production of hydrogen fuel vehicles be truly realized.

3. How to achieve sustainable development of hydrogen fuel cells

From the perspective of single-vehicle emissions, the products of hydrogen vehicles are electricity, heat and water, making them an ideal alternative energy source with zero emissions, which means they can keep urban air clean. But when it comes to the entire energy supply chain, is it an environmentally friendly energy source that protects our climate at the same time?

This depends on the production conditions of hydrogen. Currently, hydrogen is mainly produced by the electrolysis of water in junior high school chemistry, which uses electricity to decompose it into hydrogen and oxygen. Therefore, we also need to explore whether the way to supply electricity is renewable energy. If fossil fuels are used, it will eventually have a chain reaction on the carbon footprint of fuel cell vehicles using hydrogen. Then, the environmental advantages of hydrogen fuel cell vehicles compared to other fuel cells will no longer exist. Interestingly, hydrogen is also a by-product of many industrial processes. In many industrial processes, hydrogen is often regarded as waste and no longer used. Cleaning it provides a way for fuel cells to recycle hydrogen.

In addition, the improvement and safety of hydrogen transportation and storage technology will directly affect its wider use. However, given the wide range of raw materials for hydrogen production, is it possible to change the idea and miniaturize the hydrogen production equipment and reduce the cost of the equipment, directly eliminating the possible risks and high costs of transportation, and achieving local materials, local production, and local use? In theory, it is even equivalent to installing a gas station on a fuel cell vehicle. Although it is a fantasy, its application prospects are worth realizing by scientists.

It is 2020 now. I remember that at the National Two Sessions at the beginning of last year, "hydrogen energy fever" was written into the government work report, which triggered the industry's thinking. Among the domestic automakers that actively responded and practiced, Great Wall Motors was the pioneer in the front row. This is not the first time that it has shown its painstaking efforts in hydrogen energy vehicles. Therefore, the future is promising.