Efficient Synthesis of Flower-Ball Structured CuFeS2 as Advanced Anode Material for Lithium-Ion Batteries Across Wide Temperature Ranges

Transition metal sulfides stand as potential anode candidates for lithium-ion batteries offering high capacity, redox reversibility, and safety. However, cycling-induced volume variations and slow kinetics hinder their application. Here, CuFeS2 with a flower-ball nanosheet structure is synthesized via a hydrothermal method, enhancing electrolyte infiltration, Li+ transport, and cycle life. CuFeS2 exhibits a large initial discharge specific capacity of 532.4 mAh g–1 at 500 mA g–1 with 95.7% initial Coulombic efficiency, retaining an impressive 90.5% (481.6 mAh g–1) of its initial capacity after 300 cycles. Remarkably, at 2000 mA g–1 for 700 cycles, it maintains a high specific capacity of 487.1 mAh g–1 with an 89.4% capacity retention rate. Moreover, it maintains excellent reversibility at both high temperature (60 °C) and low temperature (−25 °C) and demonstrates excellent electrochemical performance even under high loading conditions. Consequently, CuFeS2 holds immense promise as a lithium-ion battery anode material, offering fast charging, safety, high capacity, and long life.