Battery science & engineering is a multidisciplinary field drawing upon physics, electrical engineering, (electro)chemistry, materials science, mechanical engineering, embedded & real-time system programming, data science, machine learning, and network engineering.
On the other hand, this is a well-defined field with a relatively enclosed community. I think people in this field tend not to interact much with people in the communities around broader fields mentioned above, so battery science & engineering is barely represented at electronics.SE, chemistry.SE, datascience.SE. But if there was a separate site, I think there is a chance to build a viable Q&A community.
I'm not sure any one of the five example questions that I proposed would be on-topic for electronics.stackexchange.com.
Proposal: Battery Science & Engineering