Yes, based on my own experience, I used to have a lot of mining applications that are similar to PI when I was active on mobile mining and I noticed a significant drop in battery life; it can even reduce the lifespan of a high-end cellphone.
And there are articles and studies that you can find online that can proved it but there are developers who claim that their cell mining application claims to be energy efficient but you have to prove that yourself. My advice is to never install more than 3 mobile mining applications, as it will shorten your cell's lifespan.