Tuning the microstructure and crystallinity of electrode materials is a great challenge and crucial for the development of high-performance sodium-ion batteries (SIBs). Herein, we develop a series of rationally designed carbon-coated V₂O₅ core-shell nanostructures (S-V₂O5-HS, S-V₂O₅-HCS, P-V₂O₅/C-SCS, A-V₂O₅/C-SCS, and A-V₂O₅/C-WCS) in which the phase (single/polycrystalline, amorphous), microstructure (hollow, solid, porous) for the V₂O₅ core, and the thickness of the carbon shell are controlled via a one-pot solvothermal method followed by a single calcination process, and the performance differences between them are systematically studied. In this composite of amorphous carbon-coated V₂O₅ well-defined porous core-shell heterostructure (A-V₂O₅/C-WCS), synergistically the amorphous V₂O₅ core accelerates ions diffusion, carbon shell boosts the electronic conductivity, and the defect-rich porous structure lowers the binding energy compared to its counterparts as confirmed by DFT calculations and electrochemical results. Out of the ordinary, the A-V₂O₅/C-WCS used as a symmetric electrode for SIBs exhibits an excellent rate capability of 148 mAh g⁻¹ at 5.0 A g⁻¹ and outstanding ultralong cyclic stability (95% capacity retentions over 3000 cycles at 2.0 A g⁻¹), when applied as a cathode (1.5–4.0 V) and anode (0.01–3.0 V) for SIBs. The A-V₂O₅/C-WCS displays a fully pseudocapacitive manner over the whole voltage thus the electrochemical performance of cathode and anode are well-matched. Impressively, the symmetric full-cell possesses a superior energy density of 219 Wh kg⁻¹ at a high specific density of 6.0 KW kg⁻¹ and superior cycling stability (95% capacity retained over 1200 cycles at 1.0 A g⁻¹), demonstrating the great potential for practical application.

调整电极材料的微观结构和结晶度是开发高性能钠离子电池（SIB）的一个巨大挑战和关键。在此，我们开发了一系列设计合理的碳包覆V ₂ O ₅核壳纳米结构（SV ₂ O5-HS、SV ₂ O ₅ -HCS、PV ₂ O ₅ /C-SCS、AV ₂ O ₅ /C- SCS, 和 AV ₂ O ₅ /C-WCS) 其中相（单晶/多晶、无定形）、微观结构（空心、实心、多孔）为 V ₂ O ₅通过一锅溶剂热法和单次煅烧工艺控制核心和碳壳的厚度，并系统地研究了它们之间的性能差异。在这种由无定形碳包覆的 V ₂ O ₅明确的多孔核壳异质结构 (AV ₂ O ₅ /C-WCS) 组成的复合材料中，无定形 V ₂ O ₅核协同地加速了离子扩散，碳壳提高了电子电导率， DFT计算和电化学结果证实，与对应物相比，富含缺陷的多孔结构降低了结合能。与众不同的是，AV ₂ O ₅/C-WCS 用作 SIB 的对称电极，在 5.0 A g ^{-1下表现出 148 mAh g -1的优异倍率性能和出色的超长循环稳定性（在 2.0 A g -1}下 3000 次循环后的容量保持率为 95% ），当用作SIB的阴极（1.5-4.0 V）和阳极（0.01-3.0 V）。AV ₂ O ₅ /C-WCS 在整个电压范围内显示出完全赝电容方式，因此正极和负极的电化学性能非常匹配。令人印象深刻的是，对称全电池在 6.0 KW kg ^{-1的高比密度下具有 219 Wh kg -1}的出色能量密度和出色的循环稳定性（在 1.0 A g 下 1200 次循环后仍保持 95% 的容量）^-1 )，展示了实际应用的巨大潜力。