The present work considers the fundamental aspects of the NiCd battery recycling process. The objective was to study temperature and atmosphere effects on the decomposition of cadmium oxide in NiCd sealed batteries’ electrodes. Initially, cellular phone batteries were physically conditioned so as to obtain a mixture of ground electrodes. This material was submitted to thermal tests in laboratory scale equipment. Tests were conducted using nitrogen as a inert atmosphere, with temperatures from 600 to 1000°C. Products from the reaction were characterized by X-ray diffraction, atomic absorption spectrophotometry and size particle distribution. High purity Cd was obtained in the condenser and a Ni–Fe–Co alloy with <100ppm of Cd was also found in the crucible. Zinc was the main impurity in the condensed material.