Dominant pseudocapacitive lithium storage in the carbon-coated ferric oxide nanoparticles (Fe2O3@C) towards anode materials for lithium-ion batteries

Abstract

A facile strategy of arc plasma followed by an annealing treatment was developed to fabricate the carbon-coated ferric oxide nanoparticles (Fe2O3@C) as the anode materials for LIBs. In the arc-discharge process, higher enthalpy of the plasma was realized by existence of active hydrogen atoms, which can greatly promote the evaporation of raw Fe2O3/solid graphite powers and give rise to the highly graphitized carbon shells. It is indicated that the core/shell nanostructure effectively preserves the structural/electrical integrity leading to the excellent cycling stability. Unlike the carbon coatings formed by wet chemical routes, such carbon layers feature dominant pseudo-capacitive behavior, stronger electric conductivity and better charge transfer ability, thus harvesting the superior rate capability. Benefiting from the structural advantages, the Fe2O3@C electrode delivers a reversible capacity higher than 500 mA h g−1 at the current density of 5 A g−1 after 500 cycles. The mechanisms of structural formation and the electrochemical activities have been revealed in details. The facile synthesis route and good electrochemical performances endow the Fe2O3@C nanoparticles with great potential to meet the requirements on high energy/power and long lifespan for LIBs.