Bremerhaven Airport (BRV), on Germany's North Sea coast, has little to no scheduled commercial passenger service today, and with that comes no lounge; the field functions mainly for general aviation and occasional charter traffic rather than the kind of routine timetable that would ever justify one.
Bremerhaven itself is a major German port and cruise city, better known for its container terminals and its cruise departures than for its small airfield. The city is home to the Deutsches Schifffahrtsmuseum, Germany's national maritime museum, and to the Columbus Cruise Center, a real and active cruise terminal that draws considerably more travelers each year than the airport ever has. Most visitors arrive by road, rail, or ship rather than by air at all, and the city's transport links reflect that port-and-rail identity more than any flight schedule.
The real nearby option for anyone who does want an airport with actual traveler amenities is Bremen Airport, roughly sixty kilometers to the south and reachable by regional train or car, which supports scheduled airline service along with a lounge and other facilities that a field the size of Bremerhaven's simply cannot support. If your trip requires lounge access, route through Bremen and confirm current hours and eligibility with your airline or card issuer before you travel, since specifics can change between visits.
Bremerhaven's own calendar runs on its port and cruise activity more than any flight schedule: cruise ship calls at the Columbus Cruise Center cluster roughly between April and October, and the city is noticeably busier with visitors and cruise passengers during that stretch. Since Bremerhaven Airport itself carries little to no scheduled passenger traffic, check its current operating status directly if you are considering it for any purpose, and plan your real air travel and any lounge needs through Bremen instead of the local field.