Phone won't turn on

I have the iPhone 5s and my phone battery ran out and turned off. When I came home I plugged it in to charge it, and the black screen with the empty battery popped up. It then went to the white screen with the black apple logo, which usually happens, but then instead of turning on and asking for my passcode, the phone turns off and the screen goes black. I have tried various outlets for my charger and doing a hard reset on my phone but no luck. It has been plugged into the outlet charging for about 30 minutes now. Please help! Thanks!