Battery joint ventures have become the hot must-have deal for automakers that have set ambitious targets to deliver millions of electric vehicles in the next few years. It’s no longer just about securing a supply of cells. The string of partnerships and joint ventures show that automakers are taking a more active role in the development and even production of battery cells. Automakers are taking a more active role in the development and even production of battery cells. And the deals don’t appear to be slowing down.