2026-10-09T01:04:02Z https://api.figshare.com/v2/oai

oai:figshare.com:article/33870742 2026-09-17T04:28:24Z category_859 portal_316 item_type_3 month_year_09_2026

Supplementary file 1_Engineering the structural and electronic properties of VO2 through Fe substitution for high-performance aqueous zinc-ion batteries.docx Govind Kumar Maurya (25001530) Amit Kumar Singh (7430552) Neha Chaudhary (787291) Sheetal Gupta (19868898) Khushwant Singh (4391845) Suporna Bhowmik (25001533) Dhirendra K. Rai (25001536) Electrochemistry aqueous zinc-ion batteries electronic structure engineering fe-substituted VO2 structural modulation Zn2+ storage vanadium dioxide density functional theory vanadium dissolution <p>Rechargeable aqueous zinc-ion batteries (AZIBs) are gaining attention for large-scale energy storage owing to safety and low cost. Among the numerous cathodes for AZIBs, VO₂ is a promising candidate due to its tunnel-like structure and high theoretical capacity; however, its practical application is limited by its low electronic conductivity. To address this issue, doping with several transition metals has been attempted; however, exploration of Fe doping is rare despite its cost-effectiveness and abundance. Herein, a series of Fe-substituted VO₂ cathodes (Fe_xV_1-xO₂: x = 0.15, 0.25, and 0.35) have been synthesized via a simple one-step hydrothermal method and systematically evaluated for AZIB applications. PXRD studies indicate a noticeable lattice expansion upon Fe substitution, providing relatively wider pathways for Zn²⁺ transport within the cathode framework. Among the investigated compositions, Fe_0.25V_0.75O₂ exhibited the best electrochemical performance, delivering a high specific capacity of 380.11 mAh g^-1 at 0.1 A g^-1, retaining 56% capacity at 5 A g^-1, and maintaining 82.75% capacity retention after 500 cycles at 2 A g^-1, significantly outperforming the pristine VO₂ cathode. Post-cycling characterization further revealed improved tolerance toward cycling-induced structural and morphological changes, while ICP-OES analysis showed approximately 92.3% lower vanadium dissolution for FeVO₂-25% than pristine VO₂. The Fe substitution effect is also rationalized by DFT calculations, which showed a modified electronic structure of VO₂, including band-gap narrowing through Fe 3d–V 3d/O 2p hybridization, consistent with the experimentally observed reduction in optical band gap. This work demonstrates that Fe, an earth-abundant and cost-effective dopant, provides an effective strategy for simultaneously tuning the structural and electronic properties of VO₂ and improving its Zn²⁺ storage performance in aqueous zinc-ion batteries.</p> 2026-09-17T04:28:24Z Dataset Dataset 10.3389/fbael.2026.1923272.s001 https://figshare.com/articles/dataset/Supplementary_file_1_Engineering_the_structural_and_electronic_properties_of_VO2_through_Fe_substitution_for_high-performance_aqueous_zinc-ion_batteries_docx/33870742 CC BY 4.0