That's been known since Emerald. It increases your chance of finding Electric Types.
That's called a Critical Capture. They added that in Black and White. Its also not a guarantee, as I've had many break out.
Found something interesting out just now. I was battling a Golett, and when I defeated it I got a message saying something like "You found a White Herb in the aftermath!" Lo and behold, I got a White Herb after the battle. Is it possible that you have a small chance of finding items after a wild battle?
THANK YOU FOR TELLING ME ABOUT STATIC.
Finding Helioptile just got 1000 times easier.