It is a flying battery!
A startup called Impossible Aerospace claims its "flying battery" drone has a flight time of up to two hours. See 'Flying battery' drone can apparently hover non-stop for two hours.
Yes, I noted the $7,000 price tag (without any accessories), but that will likely come down if the technology works and production comes up. It is just another example of the type of innovation we will continue to see as the technology of drones continues to advance.