Interface Cooperative Enhancement of PPY/Fe₂O₃@NF Composite Lithium Storage Material

The evolution of electronic technology has intensified the demand for lithium-ion batteries to achieve elevated energy density, prolonged cycling longevity, and enhanced safety. Traditional graphite anodes are inadequate in meeting these requirements. α-Fe₂O₃ possesses a high theoretical capacity and is abundantly available; however, its poor conductivity and significant volume expansion during charge-discharge cycles restrict its practical applicability. This study addresses these issues by developing a three-layer cooperative structural anode material composed of foam nickel (NF), α-Fe₂O₃, and polypyrrole (PPY). Employing a hydrothermal method, α-Fe₂O₃ nanowires were in-situ grown on the 3D framework of foam nickel, followed by electro-polymerization to achieve a dense PPY coating. The foam nickel offers a highly conductive scaffold and mechanical support, while PPY enhances conductivity, provides structural buffering, and facilitates in-situ nitrogen doping. Collectively, these components synergistically improve conductivity, mitigate volume expansion, and optimize the solid electrolyte interphase. This composite material demonstrates comprehensive enhancements in conductivity, structural stability, and interface compatibility, as evidenced by the well-preserved structural integrity after prolonged cycling, thereby overcoming the performance limitations associated with singular α-Fe₂O₃ and simplistic composite systems, and presenting novel insights and technical support for the advancement of high-energy-density lithium-ion battery anodes.