Bimetallic sulfides, as high-performance anode materials, exhibit high theoretical capacity. However, their practical application is hindered by inherent limitations, such as low electrical conductivity, sluggish charge transfer kinetics, and severe volume expansion. Interface-engineered heterostructures have emerged as a universal strategy to synergistically enhance conductive networks and suppress mechanical degradation. Carbon-based composites serve as optimal substrates due to their high conductivity and structural flexibility. In this study, we leverage the hierarchical porous architecture of expanded graphite (EG) to confine the self-assembly of Zn/Co precursors via a thiourea-assisted hydrothermal method, enabling in situ growth of Zn0.76Co0.24S nanoparticles within EG interlayers. Interfacial S–C covalent bonding, induced by π–π conjugation, establishes robust nanoscale coupling between Zn0.76Co0.24S and the carbon framework. The resulting “sandwich” heterostructure demonstrates exceptional cyclability (1086.9 mAh·g−1 after 500 cycles at 1.0 A·g−1) and rate capability (541.7 mAh·g−1 at 2.0 A·g−1). This work provides a generalizable design paradigm for high-performance multimetallic sulfide anodes through atomic-scale interface engineering.

Expanded graphite-confined bimetallic sulfide heterostructure enables high-capacity and long-life lithium-ion batteries
    Abstract
    1 Introduction
    2 Experimental section
        2.1 Material synthesis
        2.2 Material characterization
        2.3 Electrochemical measurement
    3 Results and discussion
    4 Conclusion
    Acknowledgements 
    References

• Chengqing Deng(College of Materials and Chemical Engineering, Guangxi Key Laboratory of Comprehensive Utilization of Calcium Carbonate Resources, Hezhou University, Hezhou 542899, China, School of Materials Science and Engineering, Guilin University of Electronic Technology, Guilin 541004, China)
• Xiaohui Zhang(College of Materials and Chemical Engineering, Guangxi Key Laboratory of Comprehensive Utilization of Calcium Carbonate Resources, Hezhou University, Hezhou 542899, China, School of Materials Science and Engineering, Guilin University of Electronic Technology, Guilin 541004, China)
• Feiyan Lai(College of Materials and Chemical Engineering, Guangxi Key Laboratory of Comprehensive Utilization of Calcium Carbonate Resources, Hezhou University, Hezhou 542899, China, School of Materials Science and Engineering, Guilin University of Electronic Technology, Guilin 541004, China)
• Guangchang Yang(College of Materials and Chemical Engineering, Guangxi Key Laboratory of Comprehensive Utilization of Calcium Carbonate Resources, Hezhou University, Hezhou 542899, China, School of Materials Science and Engineering, Guilin University of Electronic Technology, Guilin 541004, China) Corresponding author
• Kai Pan(School of Materials Science and Engineering, Guilin University of Electronic Technology, Guilin 541004, China)
• Jiawen Guo(School of Materials Science and Engineering, Guilin University of Electronic Technology, Guilin 541004, China)