Sick peace lilly
Your photos are out of focus. The location looks dark, the plant may have been overwatered, and it is possible the container may be too large. If the container is too large, there is too much soil for the root mass of the plant. The roots might rot if the are sitting in soil that remains too damp. In other words, there will be more moisture than the roots can handle. If so, repot the plant to one size smaller.
It will be helpful to focus on proper care. Peace lilies like to be in medium light, so we recommend placing your plant where it can get good strong indirect light. Direct sunlight will burn the leaves. When you water, do so thoroughly until you see water drain out of the bottom of the pot, and then let the top two inches of soil dry out before watering again. Here is more information on peace lily https://hgic.clemson.edu/factsheet/peace-lily/