Hi @Darik, welcome to our forum!
Your question has been translated to English as this is an International forum, please post any replies in English and it will be easier for me and other users to assist you.
Sony does not sell any spare parts to private customers, but the battery can be replaced at an authorized service centre. Do note that this is a Global user based forum and for market specific inquires such as service centre locations, please get in touch with your Local support team on the link below.
https://support.sonymobile.com/global-en/contactUs/
I hope that helps! 
