Based on this product's specifications, here are some alternatives and similar models
Battery extra digital for XIAOMI Mi Robo S50 14.8V 5.2Ah Li-ion
Summary description:
Rechargeable Li-ion battery by extra digital compatible with XIAOMI Mi Robo S50. Rated 14.8V and 5.2Ah capacity, it supplies power for extended cleaning sessions and replacement of worn or failing original packs. Intended for use in the specified robot vacuum model to restore runtime and maintain cleaning performance. Handle and install according to device instructions.