Recovery of cobalt based materials from spent Li-ion batteries and their use as electrode material for supercapacitor

Abstract

In this work, Co(OH)2 and Co3O4 were obtained to be used in coin cell-type supercapacitors from a lithium-ion battery whose cathode material is LiCoO2 for the first time in the literature. Firstly, LiCoO2 cathode material was taken from the dismantled li-ion battery, and leaching of cathode material was carried out using HNO3 and H2O2. Leaching was performed with a maximum yield of approximately 94 %. Then Co(OH)2 was precipitated in a basic medium by using a NaOH solution. Thermal analysis was applied to the produced Co(OH)2 to determine the behavior for conversion from Co(OH)2 to Co3O4. Two different Co3O4 powders were obtained as Co3O4-450 and Co3O4-1000 by calcination of precipitated Co(OH)2 at 450 and 1000 °C. Produced powders were characterized by lots of characterization methods such as XRD, Raman, SEM and BET. Three different electrode material for the coin cell type asymmetric supercapacitor cathode was made from produced powders by mixing with carbon black and PVDF. GCD, CV and EIS measurements were used evaluate the electrochemical properties of the supercapacitors. The maximum areal capacitance value of 98 mF.cm−2 was obtained at 10 mV/s scan rate in Co3O4-450 based supercapacitor.