Which thinkpads are the latest that have a removable battery? I have a T480. Any newer than this that have the removable battery?

For the X-Series, the last one was the X270. X280 onwards are all integrated batteries.

For the P-Series, the last ones were the P52 and P71.

For the L-Series, the last ones were the L470 and L570.

Fore the E-Series, the last one was the E570.