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

• Octahedral Fe 3 O 4 /FeS has been synthesized by one pot hydrothermal method. • The formation mechanism of Fe 3 O 4 /FeS was proposed. • The Fe 3 O 4 /FeS exhibits a high capacity of 530.7 mAh g−1 after 100 cycles at 0.1 C. • Fe 3 O 4 /FeS causes a low electrolyte decomposition, and has a high conductivity. • Fe 3 O 4 /FeS still held stabilized octahedral structure after 100 cycles at 0.1 C. The booming development of rechargeable lithium-ion batteries puts forwards higher requirement for stable electrode material by a cost-effective method. Herein, Fe 3 O 4 /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 Fe 3 O 4 /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 Fe 3 O 4 /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 Fe 3 O 4 (217 mAh g−1 after 100 cycle at 0.1 C). [ABSTRACT FROM AUTHOR]