The Mi Mix series will be returning to global audiences, according to Xiaomi. The next Mi Mix will launch alongside the Mi 11 Ultra, which will feature a new Silicon-Oxygen Anode battery. Apparently, the new battery technology's increased density will allow smartphones to recharge faster while being thinner than current models.
https://www.notebookcheck.net/The-next-Mi-Mix-will-receive-a-global-release-as-Xiaomi-teases-groundbreaking-battery-technology.529385.0.html
Silicon-oxygen? Seriously? I can only imagine that's some shoddy translation. And I would be willing to bet that it is a type of Li-ion cell.