This is very interesting, and if those numbers are right, straight up batteries do not appear very practical for that route. but lets consider that one does not have to complete the longest journey in the world on a single battery charge.

Any of the pacific islands could be built out with infrastructure to recharge them - afterall, sea-based wind turbines are one of the cheapest sources of power, while ontermittent, they are perfect for charging. You coupd even place something akin to an oil platform, but for charging ships.

However maybe something like hydrogen makes more sense.