As we are aware that hydrogen is the only possibility of operating the heavy-duty section of transportation (checkout the other blog) it is important to know how it actually works. Hydrogen can be employed in automobile in three main ways.
- Using hydrogen in internal combustion engines instead of diesel and gasoline.
- Hydrogen hybrid vehicles (HHV).
- Fuel cells.
This discussion concentrates on fuel cells. This can be understood as the reverse of hydrolysis. Just by passing electricity with an electrolyte solution, produces hydrogen and oxygen, combining hydrogen and oxygen with some electrolyte produces electricity. This is essentially the difference between an electrolytic (hydrolysis) and an electrochemical cell (fuel cell).
Out of the three processes discussed above, fuel cells provide more efficiency because, they are employed in an electric vehicle and the other two deals with less efficiant internal combustion engines.
Advantages
Toyota mirai
The main advantages of fuel cell is that it has higher specific energy of 142 MJ/Kg and it is higher than gasoline, diesel or batteries. As discussed earlier it has the potential in powering the aviation industry. But, the main hindrance here is the cost of production of hydrogen and storing it. Also, fuel cells convert the hydrogen and oxygen to not just water and electricity but also heat which needs cooling just like internal combustion engines whereas battery do not need such things to a greater extent.
Disadvantage
Many advancements have taken place in this field and one such thing is by using proton exchange membrane. Which transfers proton (H+ ions) from anode to cathode instead of electrons as seen in other electrochemical cells. This made the fuel cells work more efficiently. Lots of companies are working in this field Toyota is a very good example. The company has made 3000+ patents on fuel cells open so that innovations in this field develop. Toyota mirai is powered by fuel cells and they are trying to expand it by increasing the production of hydrogen in large scale to bring down the cost of hydrogen. Other companies like Honda, Hyundai are also working here.
It is interesting to note that the Asian companies are working on fuel cells and the Elon musk is totally against hydrogen-based transportation. Tesla semi truck is totally powered by batteries and promises a range of 500 miles (840 Km) which is not bad at all. But will it carry enough amount of load just like a normal truck? It is a question which we will see after the truck rolls out.