Recently, as the productionProductions of electric vehiclesElectric Vehicles (EVs) has rapidly increased, the productionProductions of lithiumLithium-ion batteriesBattery containing high-purity valuable metalsMetals (Ni and Co) is required. The number of end-of-life lithiumLithium-ion batteriesBattery has rapidly increased; therefore, there is a need to improve environmentalEnvironmental issues. However, there are limits to process changes for removing impurities and achieving high purity of diversified recycled resources in hydrometallurgical processHydrometallurgical processes for recyclingRecycling of end-of-life lithiumLithium-ion batteriesBattery. Therefore, a transition to hybrid process capable of mass productionProductions is required, and the research was conducted on matte smeltingMatte smelting and purificationMatte purification process using recycled resources. Ni and Co contained in various resources were recovered using molten iron in high-temperature smeltingSmelting process. The recovery behavior depending on the type of resource by carbon content was compared with the thermodynamic calculations using FactSageFactSage 8.2™. The alloy containing Ni and Co was concentrated through addition of sulfur and oxygen blowing and smelted into matteMatte with improved concentration of Ni and Co. An aqueous solution containing Ni and Co was obtained through a pressure oxidationPressure Oxidation (POX) leachingLeaching, and it was confirmed that the Ni and Co recovery rates were closely related to the oxidation–reduction potential and pH of the pregnant leachingLeaching solution. The leachate was highly purified into Ni and Co compound through a neutralization process, and the impurity concentration in the Ni and Co compound was maintained below 0.5%. In order to develop the matte smeltingMatte smelting and purification process utilizing recycled resources, process condition was established by METSIM engineering software.