Molecularly Engineered Porphyrin-Intercalated V₂O₅ for Advanced Sodium-Ion Battery Cathodes

Vanadium oxides are promising cathode materials for rechargeable batteries due to their high specific capacity. However, its application is hindered by the poor rate capability and cycling stability. Herein, porphyrins are employed as pre-intercalated guests to elastically modulate the interlayer spacing of the V─O skeleton. By tailoring the size of porphyrins, the interlayer spacing is effectively expanded, enhancing the structural integrity of the VO host. Experimental and theoretical investigations confirm that porphyrin intercalation not only expands the layer spacing but also establishes a strong interaction with V─O layers, thus improving the material's stability. Remarkably, sodium-ion batteries (SIBs) assembled using this novel H₂TCPP-intercalated V₂O₅ grown on nickel foam (NF) (H₂TCPP-VO/NF) deliver an impressive specific capacity of 760.7 mAh g^-1 at 0.07 A g^-1, outperforming most reported vanadium-based cathodes. This work offers valuable insights for the rational design of high-performance cathode materials capable of accommodating large-sized ions.