I had the same problem as you: My spokes were breaking at an incredible rate, something like a spoke a week, or so. In my case, I'm pretty strong at acceleration, and commuting in the city requires many accelerations, so a lot of stress on the spokes. They always broke at the elbow like yours.
I finally found the problem, and solved it without using any different material: While my wheel was true, the tension of the spokes was not even enough. If you allow the tension of your spokes to vary too much, the differences will grow over time due to use, and the tension of some spokes will rise. It doesn't take long for the first spoke to break, which again changes the tension of a lot of spokes instantly, exaggerating the problem.
My solution was to get really strict on applying even tension. As someone with musical training, I found it easiest to just let my computer play a constant tone, and tune my spokes to it. Apply several passes until there is no spoke that's significantly out of tune anymore. I alternate tuning passes with truing passes so that I get a result that's both true and in tune.
Since I'm using this method to build my wheels, my spoke problem has literally vanished (I still use exactly the same material!). A good bike mechanic can probably produce an equally even result; if you let someone build your wheel, and you get breaking spokes afterwards, you should probably go to someone else the next time, until you find someone who can make your spokes sing...