Suddenly deleted a few years ago in button cell, the surface is rusty. I touched it with my hand, and it was a little sticky. The boy matures year by year. That means your button cell is leaking. The battery has failed and can't be used. And this thing seems to be harmful. You'd better get rid of it quickly. Don't throw it again. This kind of battery seems to pollute the land. You'd better throw it into the sorting bin. Don't throw it about.