The Samsung Note 7 has been the recent subject of a recall due to batteries catching on fire. (Here are instructions for exchanging your phone.) If you haven’t yet exchanged it please note as of October 15, 2016, the US Department of Transportation, with Federal Aviation Administration and the Hazardous Materials Safety Administration announced the ban of all Samsung Galaxy Note7 smartphones on all air transportation in the United States. Meaning the device cannot be brought on a flight either as carry-on, in checked baggage or shipped as air cargo.
Beyond the Note 7, there are plenty of devices that people frequently travel with that have lithium batteries. There are some restrictions on which batteries are allowed, and whether or not they can go in checked or carry-on baggage. For example, do not put spare batteries in checked baggage. If you must gate-check your suitcase, remove all spare batteries from your baggage and put it in your carry-on.
For more information about your specific device, see the US Department of Transportation page on Traveling With Lithium Batteries.