Usually it's known to do the opposite. But to each their own as side effects with this drug are wide and varried and are known to affect sexual function, usually causing lack of interest
I never noticed it affect my own sexual urges when I was on it, but a lot of people complain about it lowering their libido. However, I know while I was on lithium, there were times when I had strong sexual urges/temptations/desires, but that was when I was headed into mania or already manic.
I don't know about other people but in me it does the opposite. Some days my interest in sex is so low it strains on my relationship with my fiance. Fortunately she knows it's something neither of us can control.