The selection of the most suitable crystal structure for ions storage and the investigation of the corresponding reaction mechanism is still an ongoing challenge for the development of Mg-based batteries. In this article, high flexible graphene network supporting different crystal structures of Nb₂O₅ (TT-Nb₂O₅@rGO and T-Nb₂O₅@rGO) are successfully synthesized by a spray-drying-assisted approach. The three-dimensional graphene framework provides high conductivity and avoids the aggregation of Nb₂O₅ nanoparticles. When employed as electrode materials for energy storage applications, TT-Nb₂O₅ delivers a higher discharge capacity of 129.5 mAh g⁻¹, about twice that of T-Nb₂O₅ for Mg-storage, whereas, T-Nb₂O₅ delivers a much higher capacity (162 mAh g⁻¹) compared with TT-Nb₂O₅ (129 mAh g⁻¹) for Li-storage. Detailed investigations reveal the Mg intercalation mechanism and lower Mg²⁺ migration barriers, faster Mg²⁺ diffusion kinetics of TT-Nb₂O₅ as cathode material for Mg-storage, and the faster Li⁺ diffusion kinetics, shorter diffusion distance of T-Nb₂O₅ as cathode material for Li-storage. Our work demonstrates that exploring the proper crystal structure of Nb₂O₅ for different ions storage is necessary.

选择最合适的离子存储晶体结构和研究相应的反应机理仍然是镁基电池开发的一个挑战。在本文中，通过喷雾干燥辅助方法成功合成了支持Nb ₂ O ₅不同晶体结构的高柔性石墨烯网络（TT-Nb ₂ O ₅ @rGO和T-Nb ₂ O ₅ @rGO）。三维石墨烯骨架提供高电导率，并且避免了Nb ₂ O ₅纳米粒子的聚集。TT-Nb ₂ O ₅当用作储能应用的电极材料时可提供129.5 mAh g ^-1的更高放电容量，约为T-Nb ₂ O ₅的Mg存储容量的两倍，而T-Nb ₂ O _5则提供了比TT更高的容量（162 mAh g ^-1） -用于锂存储的-Nb ₂ O ₅（129 mAh g ^-1）。详细研究表明，Mg的嵌入机理和较低的Mg ²⁺迁移势垒，作为Mg储存阴极材料的TT-Nb ₂ O _5的Mg ²⁺扩散动力学更快，Li ⁺扩散动力学更快，T-的扩散距离更短。铌₂O ₅作为用于锂存储的阴极材料。我们的工作表明，探索Nb ₂ O ₅的适当晶体结构用于不同离子存储是必要的。