Probably go with the people who recommend replacing it with a new battery, perhaps sending this one back for repair.
But as for me, I'd glue it using plastic epoxy and carbon fiber. Be careful - some auto shops sell textured vinyl labelled as carbon fiber. You want the real stuff. Keep in mind your $1000 investment is hanging on this one repair, and keep an eye on it. Another thing to watch out for is the pedigree of the battery. There are some fake ones being sold on eBay and similar places, and they are not as good, including tending to catch on fire.