Li-Ion batteries were a massive technological step forward from NiMH cells but were not without faults of their own—like their tendency to explode. A new Lithium-Imide technology from Leyden Energy, however, send Lithium-Ion the way of NiMH.
The problem with traditional Li-Ion batteries is that they're very susceptible to both heat degradation, wherein high temperatures generated by your quad-core, overclocked CPU's cause the electrodes in the battery react with the electrolyte resulting in diminished charge capacity, and to moisture, which reacts with the salts in the electrolyte itself to create Hydrochloric acid. Being some of the most caustic stuff on Earth, Hydrochloric acid eats through the cathode and anode sheets within the battery and causes gas build-up (which is why older Li-Ion batteries tend to bulge slightly). This degradation happens fast too, with some cells losing up to 50% of capacity within 300-500 charge cycles. Hence, you rarely see a 24-month warranty on a Lithium battery.
The new Lithium-Imide batteries from Leyden Energy, on the other hand, use a patented salt in their electrolytes that better withstands heat and doesn't react with moisture as well as a conductive graphitic foil for its cathode, rather than the traditional aluminum, for increased heat tolerance. The result? Lithium batteries that last over three years, 1000+ charge cycles, and maintain their charge capacity even as the battery nears the end of its service life. "Even if you use your battery every single day for three years," said Marc Juzkow, Leyden's VP of R&D and Engineering told Gizmodo in via phone, "you're still going to have 80% of your initial capacity remaining."