Recovery of lithium, cobalt, nickel, and manganese from spent lithium-ion batteries through a wet-thermal process

Abstract

Recycling end-of-life lithium-ion batteries (LIBs) as a problematic waste stream has become an urgent area of research worldwide. This paper details an efficient, simple, and environmentally friendly technique for metal recovery from a mixture of three types of spent LIBs cathodes. By using the carbothermal process, Li is first isolated in solid lithium carbonate with minimal emission, and to optimize Li isolation the effects of temperature, holding time, and graphite dosage are investigated. Under optimal carbothermal conditions of 700°C, 60 min, and 15% graphite, phases of CoO, NiO, Li2CO3, and small amounts of Ni and Co are formed. This stage is followed by dissolution in cold water where 94.6% of Li is recovered under optimal leaching conditions. After filtration, the residual component is reduced by the second carbothermal reduction under vacuum at 900°C for 120 min, resulting in the formation of high purity metals.