How does sperm die?

Sperm death: Well, this is got to be one of the more unusual questions here. I'm wondering in what context you want to know. Sperm, like any living tissue requires some sort of "food or energy" to survive. We also have to remain in some form of solution and not dry out. There are formulas and chemicals that can kill sperm. Here's something you can read. http://en.wikipedia.org/wiki/spermicide.