Octahedral Fe3O4/FeS composite synthesized by one-pot hydrothermal method as a high-performance anode material for lithium-ion batteries

Highlights: • Octahedral Fe₃O₄/FeS has been synthesized by one pot hydrothermal method. • The formation mechanism of Fe₃O₄/FeS was proposed. • The Fe₃O₄/FeS exhibits a high capacity of 530.7 mAh g⁻¹ after 100 cycles at 0.1 C. • Fe₃O₄/FeS causes a low electrolyte decomposition, and has a high conductivity. • Fe₃O₄/FeS still held stabilized octahedral structure after 100 cycles at 0.1 C. -- Abstract: The booming development of rechargeable lithium-ion batteries puts forwards higher requirement for stable electrode material by a cost-effective method. Herein, Fe₃O₄/FeS composite with a regular octahedral structure was synthesized by a facile one-pot hydrothermal method for and was evaluated as anode material for lithium-ion batteries. As indicated by the morphology evolution, the presence of FeS can effectively alleviate volume expansion and inhibit the agglomeration the Fe₃O₄/FeS composite during the Li⁺ insertion/extraction process. Moreover, the introduction of FeS was proved to form a high-quality solid-electrolyte interface (SEI) film by reducing electrolyte decomposition. Benefitting from the artful design of anode material, the Fe₃O₄/FeS composite exhibited superior cycling performance with a high specific capacity of 530.7 mAh g⁻¹ after 100 cycles at 0.1 C, which is much higher than that of pure Fe₃O₄ (217 mAh g⁻¹ after 100 cycle at 0.1 C).