The pictureis a little bit dark, does it get enough light?. The other thing you could try is a feet to encourage flowering,although I do find that mine has phases of flowering,

That's not a Peace Lily (Spathiphyllum), its Anthurium. Spathiphyllum does well in low light situations, but Anthurium needs much more bright light, though not direct sunlight in summer. Does not like to dry out, likes high humidity should be split and repotted every 2 years, feed with flowering houseplant food, keep away from heat sources.

My first thought, too - that isn't a peace lily, but, unlike Bamboo, I didn't know what it was.

I've had one myself, Ojibway - binned it after a couple of years, it got infested with something and the flowering was poor.