Efficient Synthesis\nof Flower-Ball Structured CuFeS<sub>2</sub> as Advanced Anode Material\nfor Lithium-Ion Batteries Across\nWide Temperature Ranges

Transition metal sulfides stand as potential anode candidates\nfor\nlithium-ion batteries offering high capacity, redox reversibility,\nand safety. However, cycling-induced volume variations and slow kinetics\nhinder their application. Here, CuFeS<sub>2</sub> with a flower-ball\nnanosheet structure is synthesized via a hydrothermal method, enhancing\nelectrolyte infiltration, Li<sup>+</sup> transport, and cycle life.\nCuFeS<sub>2</sub> exhibits a large initial discharge specific capacity\nof 532.4 mAh g<sup>–1</sup> at 500 mA g<sup>–1</sup> with 95.7% initial Coulombic efficiency, retaining an impressive\n90.5% (481.6 mAh g<sup>–1</sup>) of its initial capacity after\n300 cycles. Remarkably, at 2000 mA g<sup>–1</sup> for 700 cycles,\nit maintains a high specific capacity of 487.1 mAh g<sup>–1</sup> with an 89.4% capacity retention rate. Moreover, it maintains excellent\nreversibility at both high temperature (60 °C) and low temperature\n(−25 °C) and demonstrates excellent electrochemical performance\neven under high loading conditions. Consequently, CuFeS<sub>2</sub> holds immense promise as a lithium-ion battery anode material, offering\nfast charging, safety, high capacity, and long life.