Okay kiddo, let me explain what portable fuel cell applications are!
You know how we use batteries to power things like flashlights or toys? Well, there's another way to create electricity that doesn't require batteries - it's called a fuel cell! Fuel cells use a chemical reaction to convert hydrogen or other fuels into electricity.
Now, when we say 'portable fuel cell applications', we mean using these fuel cells to power things we can carry around with us, like smartphones or laptops or even cars!
How does it work? Well, let's take a smartphone for example. In a fuel cell-powered smartphone, there's a fuel cartridge that contains the hydrogen fuel. When you turn on the phone, the fuel cell takes the hydrogen and mixes it with oxygen from the air. This creates a chemical reaction, which produces electricity to power the phone.
Portable fuel cell applications are great because they're much more environmentally-friendly than using batteries or other fossil fuels. They also last longer and can be refueled easily - all you need is a new fuel cartridge!
So there you have it - portable fuel cell applications are just a fancy way of saying we can use fuel cells to power things we take with us, like our phones or laptops. Pretty cool, huh?