There is no storage mechanism if you die for a reason. Your best bet is to enchant your tools before you die... then die. Getting all that XP isn't supposed to be super easy. Use it while you got it, don't be so greedy.
I think they should just not be so greedy with EXP when you die. :/
I guess it would be good to be able to store it though, and enchanting something into a Bottle o Enchanting sounds more "minecraft-y" than an EXP chest or other ideas people have come up with.