A universal method was developed for leaching valuable metals from cobalt-containing spent lithium-ion batteries(LIBs).Organic materials were first removed from the spent batteries by roasting,then the roasted residue was blended with sodium sulfate and concentrated sulfuric acid.Metals in the mixture were further transformed into sulphates by sulfatizing roasting.The sulphates were dissolved in sulfuric acid solution of 5 g/L.The results showed that when sulfatizing roasting temperature reached to 500 ℃,all of Li,Co,Cu and Al in roasted residue could be completely translated into sulphates.Roasting temperature could be decreased to 400 ℃ by increasing adding amount of concentrated sulfuric acid in roasting process.Sodium sulfate did not convert to other phases when no concentrated sulfuric acid existed,but played a driving role in other metals conversion process.