Recycling of Li−Ni−Mn−Co Hydroxide from Spent Batteries to Produce High‐Performance Supercapacitors with Exceptional Stability

Abstract The intensive implementation of Li‐ion batteries in many markets makes it increasingly urgent to address the recycling of strategic materials from spent batteries. Batteries typically contain toxic chemicals and cannot be disposed of at will. In this study, Li−Ni−Mn−Co hydroxides are successfully recycled from spent Li‐ion batteries electrodeposited on nickel foam, and fully characterized using different techniques such as field emission scanning electron microscopy (FESEM), X‐ray diffraction (XRD), energy dispersive X‐ray spectroscopy (EDXS), inductively coupled plasma (ICP), and X‐ray photoelectron spectroscopy (XPS) techniques. The recycled nanostructured films are tested in a three‐electrode electrochemical system to investigate their capacitance behavior. The recycled electrodes show high capacitance of 951 F g −1 (specific capacity of 523.5 C g −1 ) at 1 A g −1 . Moreover, the recycled materials are used as positive electrodes to construct asymmetric supercapacitor devices. The device shows a coulombic efficiency of 100 %, a capacitance retention reaching approximately 90 % with excellent cycling stability after 10 000 cycles as well as reasonable power and energy densities.