Fe2O3/C-modified Si nanoparticles as anode material for high-performance lithium-ion batteries

Abstract

Silicon is widely investigated as an advanced conversion-type anode material for lithium ion batteries due to the high theoretical capacity and natural abundance. However, the practical application is limited by the intrinsic poor conductivity and serious volume change. To promote the reaction kinetics and reversibility of Si electrode, core-shell structured Si@Fe2O3/C nanoparticles are fabricated employing metal-organic-frameworks as sacrificed template of Fe2O3-embedded carbon coating layer. The carbon layer not only boosts the conductivity of Si and Fe2O3 nanoparticles but also accommodates their volume expansion during repeat lithiation/delithiation process. The metallic Fe(0) resulted from the lithiation process helps to improve the conductivity. As anode material for lithium ion batteries, Si@Fe2O3/C delivers high specific capacity (2941.8 mAh g−1 at 100 mA g−1), good cycling stability (680.7 mAh g−1 after 300 cycles at 1 A g−1) and good rate capability (423 mAh g−1 at 10 A g−1).