Massive post on where to get lithium-ion batteries everywhere in the world! Look at Post 2-5 for info, And Canada Post 123

Batteries and Chargers Rechargeable Batteries
3

EUROPE

NKON (ships to most of Europe): https://www.nkon.nl/

AKKU-TEILE : https://www.akkuteile.de/lithium-ionen-akkus/

18650UK: https://18650.uk/

I would recommend these 3 sources, since they are the most legitimate. Also, by buying from them, you will support the European economy, and will have good customer support.