PVP-assisted construction of MOF-derived NiCo₂O₄@carbon nanofiber high-conductivity networks for suppressing volume expansion toward high-performance lithium-ion battery anodes

Conversion-type anode materials based on transition-metal oxides have garnered considerable attention for high-energy-density lithium-ion batteries (LIBs) due to their high theoretical capacity and multiple reversible redox reactions; however, their practical application is impeded by severe volume expansion and structural pulverization during cycling. In this work, a polyvinylpyrrolidone (PVP)-assisted modulation strategy was developed to synthesize vine-like NiCo₂O₄@C composites, aiming to construct a highly conductive network and optimize the dispersion of metal oxide nanoparticles. The resulting anode features an ordered architecture in which MOF-derived components are firmly anchored onto carbon nanofibers under PVP guidance. The incorporation of carbon nanofibers significantly enhances electrical conductivity, while ZIF-67-derived nanostructures effectively suppress volume expansion, provide a high specific surface area, and create abundant porous channels. Benefiting from these structural merits, NiCo₂O₄@C delivers outstanding electrochemical performance, retaining 1528.5 mAh g⁻¹ at 0.1 A g⁻¹ after 100 cycles and 1400.2 mAh g⁻¹ at 1 A g⁻¹ after 500 cycles. This study offers an effective modification strategy for developing next-generation conversion-type anode materials with superior rate capability and long-term cycling stability.