How does a hydrogen fuel cell work? (AKIO TV) - Hydrogen gas, or H2, is a gas that contains a lot of chemical energy. If you ignite it, it will react with the oxygen in the air and release its energy by means of an explosion. And the only waste product is water. That's right-- no CO2, no toxic gases, just a bit of innocent water. Now of course, uncontrolled explosions are great fun. But how do we properly use hydrogen as a fuel to power machines and vehicles, for example? Well, in order to do that, we use a device called a fuel cell. A hydrogen fuel cell is a device that takes hydrogen and oxygen and uses those to create electricity. But how exactly does a fuel cell work? Let's find out. Right here, you can see my schematic drawing of a hydrogen fuel cell. On the left side, you can see there is an anode. And on the right side, there is the cathode. The anode and the cathode are hollow areas in which gas can be put. So inside the anode, this is where the hydrogen gas goes. And the oxygen goes into the cathode. In between them you'll find a catalyst, which is the green layer in this drawing, and an electrolyte. So let's see what happens when this system is turned on. So we've got the hydrogen in the anode and oxygen in the cathode. Now, the hydrogen inside the anode wants to go to the other side and meet up with the oxygen, and then react with it to form water. But there is a problem. It cannot get to the other side because there is something in between them-- the electrolyte. The electrolyte is a material that only let's positively charged things get through it. The hydrogen is not positive. You see, hydrogen atoms consist of one proton and one electron, one positive particle and one negative particle, which makes the overall particle neutral. So the hydrogen in our system is neutral and not positive. So it cannot get through the electrolyte. There is, however, a solution, which is the green layer in this drawing. This is the catalyst. Now what the catalyst does, in this case, is splitting off the electrons from the protons. So the electrons of the hydrogen atoms are removed from their protons. So now we've got a bunch of protons and electrons. The protons, also known as H+, can get right through the electrolyte because they're positive. And they can meet with the oxygen on the other side. But there is a problem. You see, these are just protons. They're not really hydrogen anymore, so they can't react with this oxygen and form water. In order to do that, the electrons that are still on the other side must be transported over to the cathode first. And clever people might have noticed that I just used the words electrons and transported. And transporting, or moving electrons, there is a name for that-- electricity. That's right-- moving electrons is what we call electricity. So we can simply connect a wire, like this, and then the electrons will simply be able to flow right through that wire to the other side. And then they will meet up with the protons. And then they can react with the oxygen to form water, which can leave the system. And now what we've got is an electric current running through a wire, which we can then use to power a light bulb, a motor, whatever. This is the power output of the fuel cell. Now, despite the fact that the fuel cell is such a clever invention, it does have some drawbacks. First of all, it gets really hot when it's in operation. And this can lead to the fuel cell potentially damaging itself if it isn't cooled properly. Another disadvantage of a fuel cell is that it's very, very expensive. You see, remember that catalyst we talked about, the green layer, well, that's actually made out of platinum, which is, of course, a very expensive material. But anyway, now you know exactly how a fuel cell works. I hope you've enjoyed this video. And of course, thank you for watching.