it will show buyers information about the vehicle’s battery, such as its composition, where its materials are from, its recycled content, and its carbon footprint.
Also
they will track the state of the vehicle’s battery health over time as the vehicle is charged and discharged. […] Future customers will be able to learn much more about the vehicle they’re buying from battery passports.
I respect the first part, but it seems like a niche audience that would care about materials sourcing. The battery health history is interesting. Service logs are one thing, but real data to show how hard it's been charged and driven is cool.
This ist gonna be an legislatory requirement pretty soon at least in EU. Every car manufacturer already has Implementes this or planned to do this in the near future.