Hi @tommy22
Wat i understand from your post you are writing about the back cover (that is how the battery cover is called on the Fairphone 5).
Wat is the one postet by @Meaghan and @Furdiburd
it is possible to buy this spare part for Fairphone directly ore from a reseller.
The advantage of a reseller is that most of them will be much faster with answering questions.
Greetings,
Tom