Dual-Heterojunctions Enhanced High Sodium Storage Capacity and Rapid Reaction Kinetics of Na₃V₂(PO₄)2F3 Cathode for Sodium-Ion Batteries
Discuss this preprint
Start a discussion What are Sciety discussions?Listed in
This article is not in any list yet, why not save it to one of your lists.Abstract
Designing advanced sodium-ion battery cathodes with high capacity and fast reaction kinetics remains a critical challenge for practical large-scale energy storage. In this work, we propose a dual-heterojunction strategy by integrating Na₃V₂(PO₄) 2 F₃-C and V 2 O 3 -Na₃V₂(PO₄) 2 F₃ interfaces into Na₃V₂(PO₄) 2 F₃ (abbreviated as NVPF) to synergistically enhance its electrochemical properties. The intimate Na₃V₂(PO₄) 2 F₃-C heterojunction provides highly conductive pathways, significantly reducing charge-transfer resistance and ensuring efficient electron transport. Meanwhile, the V 2 O 3 -Na₃V₂(PO₄) 2 F₃ heterojunction effectively regulates Na⁺ diffusion channels, stabilizes the crystal framework, and mitigates structural degradation during repeated sodiation/desodiation processes. Benefiting from this cooperative effect, the dual-heterojunction-modulated NVPF exhibits an outstanding reversible capacity, excellent rate performance, and superior long-term cycling stability compared with pristine NVPF. Specifically, the material delivers high capacity of 206 mAh g − 1 exceed its theoretical value, maintains rapid kinetics even under high current densities 24c, and retains remarkable capacity of 50 mAh g − 1 after 1400 cycles. This work highlights the effectiveness of dual-heterojunction engineering in phosphate-based polyanion cathodes, offering a promising approach for constructing high-performance sodium-ion batteries toward large-scale energy storage applications.
