Fe2O3/N-doped carbon-modified SiOx particles via ionic liquid as anode materials for Li-ion batteries

Abstract

SiOx is considered a promising alternative anode material for Li-ion batteries because of its higher theoretical capacity and safety compared with those of carbonaceous materials. In this study, SiOx with N-doped carbon containing Fe2O3 (Fe2O3/N-C@SiOx) was synthesized through mechanical milling, and its electrochemical properties and applicability as a stable anode material for Li-ion batteries were evaluated. Characterization data show that silicon, oxygen, carbon, nitrogen, and iron are shown to be uniformly distributed in the particles, which consist of amorphous SiO and N-doped amorphous carbon containing Fe2O3. Fe2O3 and N-doped carbon synergistically act as a reinforcing matrix that can mitigate internal breakdown between particles due to the volume expansion of the SiOx active materials while increasing electrical conductivity. As a result, Fe2O3/N-C@SiOx delivers a reversible capacity of 883 mA h g(-1) at 100 mA g(-1) for up to 100 cycles, corresponding to a capacity retention of 77%. Furthermore, it attains high reversible capacities of 671 and 415 mA h g(-1) at 1000 and 3000 mA g(-1), respectively, which are more than twice as high as that of bare SiOx (336 mA h g(-1)) measured at 1000 mA g(-1). These findings demonstrate the potential of Fe2O3/N-C@SiOx particles as an alternative anode material for rechargeable batteries.,[GRAPHICS],.,