Yes I don’t like the cartels but otherwise this would be a “natural cartel” because some materials are present only in some states, not in EU/USA for example. It the countries where those materials are presents, make Q with the countries that are buying the batteries, I mean the ones that don’t have the rare materials, this would prevent what you said.

Plus, if all are inside a “cartel” China won’t go to Congo to “buy the state” and uses the Congo’s resources without the approval of the other members.

Well maybe it depends on how this agreement/organization will be implemented.