If Vikings believed they had to die in battle, were there stories or rumours of vikings who deliberately died in battle
AFAIK no, and tl; dr: We don't know any positive contemporary evidence, apart from later 'rationalized' version of the traditions recorded in the 13th century Iceland, from the Viking Age that suggested the Old Norse afterlife was actually determined by how the Norse people died.
Sorry for just a link to the previous post, but I illustrated the possible complexity of Old Norse afterlife notions in this question thread, Getting into Valhalla- representations of Dane religion in the show “The Last Kingdom”.