The singer is said to have written down her feelings in a book since her marriage to the actor broke down at the end of 2011 and intends to use the notes for her third album.
A source told The Sun: "Ever since problems started to emerge, she penned her thoughts in a diary which she goes back to to draw upon for lyrics for her songs.
"She has always said that writing is almost a form of therapy for her and she would often be found in her dressing room on tour writing in her diary."
They added: "She spent a lot of time in Hawaii over Christmas writing lyrics to two of her latest tracks."
Perry recently revealed that she plans to take take time off to "live a little" before she starts work on the follow-up to Teenage Dream.
> Rihanna comforting Katy Perry over Russell Brand divorce
Watch the music video for Katy Perry's latest single 'The One That Got Away' below: