Primary batteries for implantable pacemakers and defibrillators

The lithium-iodine battery is established as the standard system for low-rate implantable applications, namely pacemakers because of its excellent volumetric energy density. Within defibrillators/cardioverters lithium-silver-oxovanadium (SVO) and lithium-manganese-dioxide (MDX) high-rate batteries are in use. The concept of a hybrid system which makes use of a high-rate battery and a low-rate battery within one application is described. Experimental results obtained from a MDX battery and a lithium-iodine battery, both with the same dimensions, are showing that MDX batteries of that size are able to combine excellent volumetric energy density and medium power ratings. Energy densities of 650 mWh/cm3 for the MDX battery with a lode of 30 kΩ to an end voltage of 2.5 V have been confirmed. These results show the potential of lithium-manganese-dioxide batteries to be used as low-rate and medium-rate sources within implantable applications.