Abstract:
Today Lithium-ion batteries (LIBs) are widely used in many portable electronic devices,
hybrid electric vehicles, and electric vehicles due to their unique features. However, the
rapid increment in the disposal of used LIBs to the environment causes severe damages to
the environment due to the presence of heavy metals. Thereby environmentally friendly
recycling processes are important for LIBs in aspects such as recovering valuable metals
from spent LIBs. In this work, a composite electrode material prepared using cobalt oxide
(Co3O4) and reduced graphene oxide (rGO) synthesized respectively from cathode and
anode material of spent LIBs is described. The battery type considered here was Sony
Phone Battery (AGPBO16-A001). Cathode material was subjected to an acid leaching
process using 2M H2SO4 along with 10% H2O2 followed by collective precipitation. The
pink colour precipitate, obtained at pH 1.5 was confirmed as CoC2O4 using X-ray
diffraction technique, Fourier-transform infrared spectroscopy, and X-ray fluorescence
data. Subsequently, the annealed sample at 450 0C for 2 hours was undergone with the
above tests and conformed as Co3O4 with a crystallite width of 17.7 nm. rGO was
synthesized from the anode material using sonication assisted oxidation of graphite. rGO
showed an interlayer spacing of 3.4 A0 and a crystallite width of 7 A0
. Composites were
prepared on a copper foil by varying the mass ratio of rGO and Co3O4. All the grown
samples were examined for cyclic voltammetry measurements in the same photo
electrochemical cell. The best electrochemical performance was shown by the composite
with the mass ratio of rGO: Co3O4, 1:4. In future methods will be investigated to improve
the capacitance of the composite electrode material.
Keywords: Lithium-ion Battery, Composite, Acid leaching, Capacitance
