Cars powered by standard internal combustion engines are slowly giving way to other, more modern and environmentally friendly solutions. Among them are, of course, electric cars and hybrids. In recent years, however, fuel cell electric vehicles have also become very popular. How do such cars work and what are their main advantages?
What is a fuel cell electric vehicle?
FCEV or "Fuel Cell Electric Vehicle" is an acronym describing hydrogen cars. Currently, we can observe a very dynamic development of this segment of the automotive market. Until recently, fuel cell propulsion was offered only in a few selected models – the pioneers in this regard were the Japanese brands Toyota with the Mirai model and Hyundai with the Nexo SUV. Today, however, the market for vehicles of this type is much more extensive, due in part to their environmental friendliness and efficiency.
The way hydrogen cars work is very similar to that of electric cars. The most important difference comes from the way energy is generated. In FCEVs, the energy needed to power the engine is generated by a chemical reaction in which hydrogen combines with oxygen to form water. In order for this reaction to occur, the hydrogen must first be stored in a tank – it can be refueled exactly the same way as gasoline or diesel.
See also: Advantages and disadvantages of hydrogen fuel for the car
How do fuel cells work?
Interestingly, although such a solution is only now gaining popularity in the automotive world, the principle of fuel cells was first described as early as 1838. It was developed by German-Swiss chemist Christian Friedrich Schönbein. The cell consists of two electrodes – an anode and a cathode in the form of carburized paper coated with platinum. The electrodes are separated by an electrolyte or a special electrolytic membrane. When hydrogen is in the cell (to which it must be fed beforehand), it is oxidized. This is a chemical reaction involving the donation of electrons by the atoms or ions of an element – in this case, hydrogen.
As a result of oxidation, hydrogen cations and oxygen anions are produced. Due to the presence of the electrolyte inside, it is possible to flow protons from the cathode to the anode and block oxygen anions, among others. When hydrogen cations come into contact with the cathode, they react with oxygen anions, creating water. Electrons from the anode, on the other hand, after passing through an electrical circuit, produce energy used to power the motor.
See also: Expanded foams for car battery elements
Fuel cells vs. galvanic cells – basic differences
A fuel cell generates electricity as a result of the hydrogen oxidation process. Although the goal is the same for galvanic cells, the processes involved in the two technologies differ significantly. Unlike batteries and accumulators, which are used in galvanic systems, fuel cells do not need to be charged. This means that they can start operating virtually as soon as fuel is supplied. When it comes to refueling hydrogen, the whole operation looks virtually the same as refueling gasoline or diesel. The most important difference, however, is that hydrogen is counted in kilograms, not liters. It is also important to control the rate at which the hydrogen flows through the dispenser – if the supply is done too quickly, a very dangerous increase in temperature may occur.
See also: Shock absorbers for automotive hydrogen storage tanks
The future of hydrogen in automobiles
Hydrogen cells did not find widespread use for a long time – until the 1960s. Over time, however, their potential was noticed and they began to be used e.g. in NASA spacecraft. Nowadays, they can be found mainly in the batteries of electric cars, which is associated with a considerable number of benefits. The most important advantages include, first of all, the reduction of harmful emissions. In addition, the hydrogen tank is extremely light: 120 liters of this gas can weigh as little as 5 kilograms, which is of considerable importance in terms of efficiency, operation and potential range of the electric car.
It is hard not to notice the very dynamic development of the hydrogen automotive segment in recent years. Such solutions have great potential – it may happen that in the future they will completely replace currently used technologies. However, it is important to mention certain limitations, which at present still pose a considerable challenge. First of all, we need to face the problem of a low availability of hydrogen, which translates into a high price. Despite the fact that it is the most common element in the universe, obtaining it on Earth with current technologies is quite problematic. Another challenge is the operating temperature of the gas, which in low-temperature cells should reach as high as ca. 250°C. As a result, each time the engine is started, it is necessary to heat it up, which can take several to several dozen seconds, depending on the specific model.
Knauf Automotive – innovative solutions for the cars of the future
At Knauf Automotive, we offer innovative processing methods for EPP foamed plastic, which can be used to support green powertrain solutions, among other things. This makes it possible not only to produce standard components with significantly improved properties and technical parameters, but also to design modern solutions for cars of the future. Parts made from EPP foam provide effective thermal insulation and excellent protection against shock and damage.