I did some looking around but didn't find any hard shell cases for a folding bike. Have you looked into Tern its a semi ridged case. Or they have a flight suit that protects the bike and you can pack in a standard size suit case. Also I reached out to A2B to see what they recommend as far as hard shell cases.
@Kristi, Due to the laws governing transporting Lithium batteries, you can't ship the bike and the battery on a passenger flight at this time. The battery would need to be removed and shipped ground freight, unfortunately.