A low temperature solid state reaction to produce hollow MnxFe3-xO4 nanoparticles as anode for lithium-ion batteries

Hollow MnxFe3-xO4 nanoparticles (NPs) with an average size of 15 nm are produced from the solid state reaction of Fe3O4-Mn3O4 heterostructures. These heterostructures are synthesized through the seeded-growth of Mn3O4 crystal domains on the surface of hollow Fe3O4 NPs obtained by the nanoscale Kirkendall effect. Fe3O4-Mn3O4 heterostructures are subsequently annealed at 500 degrees C, enough temperature to promote the interfusion of Fe and Mn ions, but without compromising the hollow geometry. MnxFe3-xO4 nanostructures are tested as anode in lithium-ion batteries (LIBs), delivering large lithium storage capacities and high-rate capabilities of 1054 mAh g(-1)( )at 0.1 A g(-1) and 369 mAh g(-1) at 5 A g(-1). Additionally, hollow MnxFe3-xO4 NPs display long cycling stability, with a capacity up to 887 mAh g(-1) at 0.3 A g(-1) after 450 cycles. The excellent performance of hollow MnxFe3-xO4 NPs as anode for LIBs is associated with their crystal structure, composition, and the presence of carbonized ligands, which further promote electrical conductivity and buffer the volume changes during cycling. Additionally, the small particle size and hollow morphology improves the lithium kinetics, structural stability and cycling performance.