Preparing graphene from anode graphite of spent lithium-ion batteries

With extensive use of lithium ion batteries (LIBs), amounts of LIBs were discarded, giving rise to growth of resources demand and environmental risk. In view of wide usage of natural graphite and the high content (12%–21%) of anode graphite in spent LIBs, recycling anode graphite from spent LIBs cannot only alleviate the shortage of natural graphite, but also promote the sustainable development of related industries. After calcined at 600°C for 1 h to remove organic substances, anode graphite was used to prepare graphene by oxidation-reduction method. Effect of pH and N2H4·H2O amount on reduction of graphite oxide were probed. Structure of graphite, graphite oxide and graphene were characterized by XRD, Raman and FTIR. Graphite oxide could be completely reduced to graphene at pH 11 and 0.25 mL N2H4·H2O. Due to the presence of some oxygen-containing groups and structure defects in anode graphite, concentrated H2SO4 and KMnO4 consumptions were 40% and around 28.6% less than graphene preparation from natural graphite, respectively.