The high theoretical capacity of transition metal-based compounds makes them promising candidates for lithium-ion battery (LIB) anodes. Among them, iron selenide (FeSe2) has attracted considerable interest because of its excellent electrical conductivity and superior lithium storage capacity. However, pristine FeSe2 suffers from rapid capacity fading and structural instability during repeated cycling. Thus, this study used a facile solvothermal method to synthesize a FeSe2@rGO composite with enhanced structural integrity and electrical conductivity. By incorporating reduced graphene oxide (rGO), the composite demonstrated improved charge transfer kinetics and mechanical robustness. Morphological and structural characterizations were performed using scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy analyses (XPS), which confirmed the successful formation of the composite and its uniform distribution. Electrochemical properties were evaluated using cyclic voltammetry (CV), galvanostatic charge-discharge, long-term cycling, and electrochemical impedance spectroscopy. The optimized FeSe2@rGO electrode delivered a high reversible capacity of 971.95 mAhg-1 at 500 mAg-1 after 350 cycles. The underlying charge storage mechanism was investigated using scan rate-dependent CV, which revealed a dominant capacitivecontrolled contribution at higher scan rates. The study findings indicate that the FeSe2@rGO composite can serve as a high-performance anode material with excellent cycling stability and rate capability, providing a viable strategy for the development of advanced LIBs.

Enhanced electrochemical performance of FeSe2@rGO composites as anode materials for Lithium-ion batteries
    Abstract
    1 Introduction
    2 Sample preparation
        2.1 Synthesis of FeSe2
        2.2 Synthesis of FeSe2@rGO composite
        2.3 Materials characterization
        2.4 Electrochemical measurements
    3 Result and discussion
    4  Conclusion
    References

• Joon Ha Moon(Department of Chemistry and Research Institute of Molecular Alchemy, Gyeongsang National University, Jinju 52828, South Korea)
• Seunghui Lee(Department of Chemistry and Research Institute of Molecular Alchemy, Gyeongsang National University, Jinju 52828, South Korea)
• Honggyu Seong(Department of Chemistry and Research Institute of Molecular Alchemy, Gyeongsang National University, Jinju 52828, South Korea)
• Geongil Kim(Department of Chemistry and Research Institute of Molecular Alchemy, Gyeongsang National University, Jinju 52828, South Korea)
• Youngho Jin(Department of Chemistry and Research Institute of Molecular Alchemy, Gyeongsang National University, Jinju 52828, South Korea)
• Chaeweon Lee(Department of Chemistry and Research Institute of Molecular Alchemy, Gyeongsang National University, Jinju 52828, South Korea)
• Byeong Hwi Ahn(Department of Chemistry and Research Institute of Molecular Alchemy, Gyeongsang National University, Jinju 52828, South Korea)
• June Young Jang(Department of Chemistry and Research Institute of Molecular Alchemy, Gyeongsang National University, Jinju 52828, South Korea)
• Seung-Ryong Kwon(Department of Chemistry and Research Institute of Molecular Alchemy, Gyeongsang National University, Jinju 52828, South Korea)
• Jaewon Choi(Department of Chemistry and Research Institute of Molecular Alchemy, Gyeongsang National University, Jinju 52828, South Korea) Corresponding author