LiIon batteries are all the rage as well as some exotics for the next step in Hybrids. There is another technology that has been around for tens of years. These are Nickel Hydrogen batteries and yeah I know all about NiH2 batteries as I cut my teeth on them years ago, with their individual Inconel pressureized cells. These are different, low pressure stacked cells, and they still have the same incredible cycle life (I myself tested NiH2 batteries with 44K cycles at 80% DoD). The company behind these batteries is named HERA (http://www.herahydrogen.com/en/products_ni-h2-battery.html) and they are advertising 3K cycles at 100% DoD and no self discharge. And they are targeting hybrid cars. NiH2 batteries are really rechargeable fuel cells and there are literally hundreds floating overhead in space powering LEO satellites.