I bent the battery a bit, is it still safe?

Today I replaced the rear housing on my iPhone 6 as the original was bent and badly dented. However, when I took out the battery, both adhesive strips broke immediately, and I had to heat it up with a hair dryer and peel off the battery. But it was very difficult, and the battery got bent near the top. It wasn't bent very far, maybe 20 to30 degrees. When I was done with replacing the housing I bent the battery back into shape and installed new adhesive strips, and it works fine, it charges, holds a charge well, and shows the percentage. The battery was never punctured or torn, just bent. Is it safe to use or should I buy a new one?