My Prius II is 15 years
My Prius II is 15 years working. It has a NiMH-Battery and the battery is still alive. Im tacking every refueling and the consumption since the first day. consumption stays constant, a indicator recuperation is working fine.
A Lithium-battery will degrade in time, don't like to be charged full and don't like to be empty. It hates cold and hot temperatures, high charge-/discharge-rates. Lithium batteries are fine in portables, but in rough automotive environment, from my opinion, i don't thrust in a 15-year-lifetime of a Lithium-battery.