Towards Sustainable Battery Recycling: Selective Desorption of Nickel(II) and Cobalt(II) from Amino-Polycarboxylate Derivate Ligands in Model Systems

Abstract

Inter alia due to the high demand for lithium-ion batteries, the required critical heavy metals have become a scarce resource. Consequently, effective recycling processes that enable the recovery of such materials are of high interest. A silica adsorbent functionalized with amino-polycarboxylate derivate ligands (HSU331) was applied in order to selectively adsorb nickel(II) and cobalt(II). Subsequently, suitable parameters for a pH-swing desorption were investigated. Maximum desorption efficiencies for Co(II) were achieved at pH = 2.7 (72 %) and for Ni(II) at pH = −0.5 (94 %). These results were used for the design of a pH-shift desorption process in order to selectively recover Co(II) and regenerate the adsorbent after simultaneous adsorption of Co(II) and Ni(II).