Is the expanded battery causing my Note 2 to switch off randomly?

[AC Question]

I am using the Note 2 for a while for emails and messaging. A couple of weeks back, i noticed that the batter of the phone has expanded and the back cover barely fits the phone. Could this also be a reason for the phone randomly switching off while in use? I can hardly use the phine anymore.

Whats ur suggestion? Should i try buying a new battery. I dont have any other apps than the basics installed on it. Its a 2013 phone.

Thanks!