If I ram two ball together in a tube to produce some kind of energy when they collide, what material should the balls be made out of? and they need to produce and also survive to collide again....and again and so on....

Rubber.

hell yea

 

rubber wont create any electrical charge or heat though....good on the last long part though

You didn't mention either of those things. They will produce heat, though not very much. When you crash two things together some of their kinetic energy is going to be converted into other forms of energy, like heat, noise etc. Is there a specific type of energy you want to be produced?

i was thinking static electricity . but unsure really.

foam covered lead balls. the lead will allow you to build up kinetic energy and the foam will keep the collisions inelastic. it will be particularly good at producing heat(good as in efficient in transforming kinetic to heat).

I will hook it up to a machine that will shake the tube up and down. Will I ever run out of electrons ? Would I need the tube be something that can provide more electrons to be pulled to the balls? Does that even make any sense?

 

btw, is there a thin, flexable kind of sheet of metal that the static charge can go through? But still have the ability to bend when hit by a ball?