Beyoncé used the alter ego Sasha Fierce as the title of the second disc of I Am... Sasha Fierce.
Released in 2008, I Am... Sasha Fierce was structured as a double album. The first disc, I Am..., focused on more personal and emotionally direct songs, while the second disc, Sasha Fierce, represented a bolder stage persona.
Beyoncé described Sasha Fierce as an alter ego associated with her performance confidence. The project included “If I Were a Boy” and “Halo” on the I Am... disc, plus “Single Ladies (Put a Ring on It)” and “Diva” on the Sasha Fierce disc.
Dangerously in Love is an album title, not the name of this persona. “Queen B” is a common nickname, but it is not the formal title of the second disc.