TABLE OF CONTENTS The nickel-cadmium battery cell is constructed with a sintered positive nickel electrode and a sintered or plastic-bonded cadmium negative electrode. These electrodes are interleaved with a highly porous separator which absorbs all the free electrolyte. The battery has an energy density of 50 Wh/kg and a comparatively high power density of 200 W/kg. It is capable of accepting high charge and discharge rates, and this had led to interest from some electric vehicle developers. Nissan have reported 15-min recharge times for batteries with special finned walls designed to dissipate the heat generated during charging. Such high charging rates require careful control and management of battery temperature, voltage and time of charge.
The battery peak power reduces with increased depth of discharge and the number of deep discharge cycles obtainable is reported as being as high as 2000. This long lifetime offsets, to some extent, the high battery cost. Battery prices, when high-volume production batteries appear, seem likely to be high compared to those for nickel-zinc.
Nickel-cadmium battries are available in small production quantities from a number of suppliers; as a result they have been used in a number of electric cars. Peugeot-Citroen is probably the largest user in the electric version of the Peugeot 106, of which some thousands have been sold since production started in October 1995. GM and Renault have also considered their use and Pivco Industries, a Norwegian company in which a majority interest was recently acquired by Ford, have produced the Th!nk zero-emission city...
