Self-assembly of 2D sandwich-structured MnFe2O4/graphene composites for high-performance lithium storage

In this study, two-dimensional (2D) sandwich-structured MnFe2O4/graphene (MFO/GN) composites are synthesized by a facile in situ solvothermal approach, using cetyltrimethylammonium bromide (CTAB) as cationic surfactant. As a consequence, the nanocomposites of MFO/GN self-assembled into a 2D sandwich structure, in which the interstitial cluster structure of microsphere-type MnFe2O4 is sandwiched between the graphene layers. This special structure of the MFO/GN composites used as anodes for lithium-ion batteries will be favorable for the maximum accessible surface of electroactive materials, fast diffusion of lithium ions and migration of electron, and elastomeric space to accommodate volume changes during the discharge–charge processes. The as-synthesized MFO/GN composites deliver a high specific reversible capacity of 987.95 mA h g−1 at a current density of 200 mA g−1, a good capacity retention of 69.27% after 80 cycles and excellent rate performance for lithium storage.