In a speech to Tesla Gigafactory Berlin employees during the factory's opening ceremony, Elon Musk confirmed that they are exploring manganese as a cathode material. In order to scale EV batteries to the 300 terawatt-hours of annual production needed to achieve sustainable transportation, he said, alternatives to affordable LFP battery materials will be needed.
https://www.notebookcheck.net/Tesla-s-Elon-Musk-says-new-manganese-battery-may-be-key-to-scaling-EV-production.609617.0.html