Can this battery be used with the Canon SL2? 

Good morning, two days before Christmas Eve, so first of all I wish you a Merry Christmas and a peaceful start to the New Year 2021, which may bring you the best of health and great contentment. And now to the question about the Olympus connection. I find it strange that Amazon is forwarding this question to a user of CANON EOS full-frame cameras. I have very little knowledge of other camera connections. All I know is that you are in good hands with Olympus, they are all high-performance precision mechanical and optical devices. The question of the compatibility of the K&F Concept lens with Olympus can only be answered by Olympus or Foto-Walser as the importer and sales partner of K&F Concept. However, based on decades of photo experience, I can imagine that there can be no adapter option from Canon EOS to Olympus bayonet. The connections are fundamentally different with their electronic transfers from the lens to the camera and in the number of copies. I haven't checked whether this lens even has an Olympus mount. A suitable Olympus connector would be perfect though. Just ask Olympus or Foto-Walser. Incidentally, Amazon is showing the wrong lens here, I don't have a manual 14 K&F Concept, but the AF version, and it works great with EOS. I wish you the best of luck with your research. One more thing, I'm not bothering to make a video answer as I just wanted to answer your question and not a free promotion for the lens. And the text is enough for that. Have fun and success with the Olympus products. 

Hello, according to research you need an Olympus OM Lens Mount to Micro Four Thirds Mount Adapter for this combination. 

Don’t forget that it’s a manual lens adapter. Works with full manual lenses. If your lens has no physical aperture ring, you cannot control it from your camera. 

no it will not the eos-r has a different mount