Setting different email address on LG G3
Obviously not. It is even possible to add a variety of email accounts on your LG G3 including personal email and work email . But for your case, simply add a new adress. Create your secondary email adress and delete the main adress (from the phone: settings > account > Google > [your address ] > delete). 

Now you have two addresses, one on the computer, the other on the phone.