80% of cadmium currently produced is used in rechargeable nickel-cadmium batteries: Sealed Rechargeable Nickel Cadmium Battery Cells (1969). However, they are gradually being phased out and replaced with nickel metal hydride batteries: High power nickel-metal hydride batteries and high power electrodes for use therein (1999).
Cadmium was often used to electroplate steel and protect it from corrosion. It is still used today to protect critical components of aeroplanes: Cadmium electroplating solutions (1960).
Other past uses of cadmium included phosphors in cathode ray tube colour TV sets (High efficiency blue-emitting zinc cadmium sulfo-selenide phosphor (1949)), and yellow (Light- and weather-resistant yellow cadmium pigment (1965)), orange (Stabilized Cadmium Pigments (1976)), and red (Process of making cadmium red pigment (1940)) pigments.
Cadmium absorbs neutrons and so is used to control neutron transport/contrast in nuclear fission, spectroscopy, diffraction, shielding and radiography: Cadmium containing neutron screen (1966).
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All patent information has been obtained from Espacenet (European Patent Office).