Different suppliers get different deals. And what deals you get can change from time to time. Today I expect if Ford wants to have batteries they will have to sign long term contracts - there are no enough batteries in the world and so someone needs to make a factory and that in turns means they want assurance they will sell enough batteries to make the factory worth the cost. I expect in 2040 plenty of battery capacity will exist in the world and so Ford will change to just ordering batteries from whoever can make them. For now though they need to sign long term contracts of some sort to ensure they get enough batteries.
Different suppliers get different deals. And what deals you get can change from time to time. Today I expect if Ford wants to have batteries they will have to sign long term contracts - there are no enough batteries in the world and so someone needs to make a factory and that in turns means they want assurance they will sell enough batteries to make the factory worth the cost. I expect in 2040 plenty of battery capacity will exist in the world and so Ford will change to just ordering batteries from whoever can make them. For now though they need to sign long term contracts of some sort to ensure they get enough batteries.