I have a 2006 Chrysler Sebring Sedan 2

I have a 2006 Chrysler Sebring Sedan 2.4 engine. I was driving on the interstate and suddenly began to lose acceleration. RPM's went up but speed went down. I could only keep it at 20-30 mph with the gas pedal floored. There was a loud rattling sound coming from under the hood. I drove a few miles like this and the car died at a stop light. I got it started up again and got it to the next stop light where it died and would not start again. I had it towed home and hooked up a battery charger. The battery is not charging and is completely dead. The engine will not even turn over. I get absolutely nothing when I turn the key. I checked the alternator belt and it appears to still be on the pulley and it is tight. Is it possible this is a timing belt or am I looking at alternator/battery or another issue?