LiFePO4 AA Batteries

Interesting new 1,5V rechargable battery on RiceHigh's Pentax Blog:

link

Of interest to photographers on the battery front, I believe that JCB ( who recently launched a complete household battery range in the UK), are going to be bringing out a 1.5 or 1.6v NiMh AA rechargeable battery next year. Currently these batteries are 1.2v - 1.3v from all manufacturers, but because of this don't always perform well in some appliances needing closer to 1.3v -1.4v to work effectively. The voltage(s) at the proposed new level would mean they would perform at the level that 'new' alkaline batteries perform at. Unlike alkalines the voltage wouldn't drop much as the capacity is used up. Should be very popular.

lithium iron phosphate is an interesting cathodic material.
It lets to have a very flat charge/discharge curve, so the voltage is not related to the amount of charge in the cell.
furthermore, increasing the dischage current means only reduce only the capacity, and not the voltage.

But, moreover, LiFePO4 is much safer than cobalt oxides now in the batteries.