Dramatic increase of raw material costs changes pricing of LEV batteries. Lithium batteries become relatively cheaper.
In spring of 2007 something happened that was not imaginable some years ago––raw material prices of nickel, aluminum, copper, and cadmium rose significantly, resulting in a price increase of nickel-cadmium (NiCD) and nickel-metall-hydride (NiMH) batteries. Manufacturers are forced to raise prices dramatically. As a result, there are lithium batteries around at even lower price than NiMH batteries. A comparison was made between the Panasonic NiMH D-Cell and the Sony Lithium Ion 18650 cell at a German manufacturer of battery packs.
If now the UN classifies NIMH battery packs as dangerous goods just as Lithium battery packs, the last advantage of NiMH batteries will disappear.
Lithium batteries are not only lighter, but also have a better charging and discharging coefficient. Therefore they do not heat as fast when charging and discharging. Lithium batteries have a higher potential of durability. A lower self-discharge compared to nickel batteries means that they are still ready to use even after a long time of not being used.
Security is a critical point for lithium-cobalt systems. But these systems are not used anymore in current LEVs. They have been replaced by much more secure lithium-manganese and lithium-iron-phosphate technologies. During the ExtraEnergy test such batteries had partially much better results than comparable NiMH batteries. However, the security does not only depend on the chemistry, but also on the design of the cells and the whole pack.
Report by Hannes Neupert (PDF 3.1MB)
June 11, 2007