Why not electric motors to power airplanes?

I caught part of a show regarding non-conventional automobile fuels, including fuel cells, high powered electric cars (very fast and quiet), hydrogen, and very high mileage/high powered vehicles (e.g. 140 MPG with lots of horses). After listening to this for a few minutes, it seems like electric motors have something to offer to aviation. Thanks

Air powered car??????????????

Why don’t the auto makers just make a car that runs off of pure oxygen? Wouldn’t it be cheaper to make a car that takes in air form outside. Separates the nitrogen and compresses the oxygen using that for the combustion instead of putting thousands of dollars in to hydrogen fuel cell technology and electric cars? all it would require are storage tanks and a highly efficient air compressor as well as a slightly modified engine.

Why Hydrogen when we have Electric?

Why are we spending billions to develop Hydrogen fuel cell cars, which is a big unknown, when we have the technology to develop better and more effiecient Electric cars? Zero emissions car available, TODAY! Tesla motor was able to make a car to go 250 miles on a single charge. Image the possiblities if we invested further money into the technology and rid ourselves of the dependency of foreign oil. Energy concerns can also be addressed with new developments from solar, wind and water sources. With Hydrogen cars you are dealing with unknowns and there's no way of telling when they would be ready for production. Even when it is ready, how are people going to get the hydrogen fuel. I'm sure the big oil companies will be more than happy to control the distribution on that as well.

Alternate fuel options for future vehicles?

It seems that the much touted hydrogen fuel cell won't be the savior that we once thought. It costs a lot of money to manufacture hydrogen, and it requires burning coal, which creates pollution (at the factory, not in the car), plus they can't store enough energy to make the car go over 50 mph. So what are we left with? Electric cars have same problem-storage batteries aren't sufficient to power a car for long periods of time. Solar power seems impractical (what if it's cloudy or raining?) and anti-matter is so expensive to produce it's nothing more than a pipe dream. So what will we use to power our cars in the future? Magnetic levitation? Nuclear fusion? Some technology on the drawing boards we haven't seen yet?