Battery safe to use?

About a month ago, I took out a brand new battery from an iPhone 5s I was fixing. Upon the removal of the battery, I couldn't ignore the fact that I had bent the battery ever so slightly. On that note, I then proceeded to push the slightly bent corner back into place as best as possible. The battery still works, but I was curious if the battery is still safe or even recommended to continue using. I will provide pictures.