Found a link over on gas2.0 pointing toward Firefly Energy. They are working toward improved battery technology, taking a different tactic than many seem to be. Instead of new metals (lithium, etc.), they are taking the same old lead based chemistry that we have known for years and reformulating how it is made.
They are claiming lighter weight, more efficiency, more power, etc. They are a tractor trailer battery coming to the market later this year, with talks with other industries. They seem aware of the marine world (there are mentions on their site) along with electric vehicles, etc.