Lithium is used in an incredible range of battery chemistry. They are most definitely not all the same. I recently saw a demonstration of a "Lithium-Air" battery that uses the oxygen in room air as the oxidizer. It had about 5 times the energy density of other Lithium batteries (although this one had the notable flaw of not being rechargable
Even LiFePO4 cycle life and density also vary tremendously usually due to different manufacturing methods, additives, and quality. There's an incredibly number of really bad LiFePO4 batteries being made in China
. Most, fortunately, don't make it to the US or Europe
Batteries are getting a huge amount of attention. ARPA-E the US government's research funding
arm has a special program just for electric
vehicle batteries. Here's a list of the projects they funded in the last year. VC's are also pouring money
into the field.
Five years from now, there will be even better - much better - battery choices for boats.