MoS ₂ nanocage anodes synthesized by a bubble-template-assisted method can provide a large expandable area to stabilize the electrode structure during cycling.

The proposed powder exfoliated monolayer-rich MoS₂ electrode exhibits remarkable specific capacities and stable cyclic performance.

Unique hierarchical mulberry-shaped Na₃V₂(PO₄)₂O₂F@C nanocomposite was fabricated by a rapid microwave-assisted low-temperature refluxing strategy. The V(acac)₃ reverse micelle systems in the water-in-oil microemulsions played key roles in forming the self-assembly architectures. The prepared Na₃V₂(PO₄)₂O₂F@C nanoparticles with the anisotropic growth along the [002] direction were in-situ encapsulated in carbon shells, which greatly contribute to fast Na⁺/e⁻ transfer in electrodes. And the self-assemblies with high structure stability help to improve the cycle performance and mitigate voltage fading. The initial discharge capacity of Na₃V₂(PO₄)₂O₂F@C as cathode for sodium ion batteries is about 127.9 mA h g⁻¹ at 0.1 C. Besides, a high rate performance with a capacity of 88.1 mA h g⁻¹ at 20 C has been achieved, and the capacity retains 82.1% after 2,000 cycles. In addition, the reaction kinetics and Na⁺ transportation mechanism of Na₃V₂(PO₄)₂O₂F@C were preliminarily investigated by the ex situ X-ray diffraction, X-ray photoelectron spectroscopy and galvanostatic intermittent titration technique. More interestingly, when coupled with Li, the fabricated hybrid Li/Na-ion batteries also exhibit excellent rate and cycling performances. The proposed rapid refluxing strategy to synthesize mulberry-shaped Na₃V₂(PO₄)₂O₂F@C opens up a new opportunity to develop high-performance electrode materials for the energy storage systems. 本论文采用快速微波辅助低温回流策略制备了桑椹形Na₃V₂(PO₄)₂O₂F@C纳米复合材料. 研究表明微乳液中的V(acac)₃反胶束体系 对该自组装结构的形成起到了关键作用. 制得的Na₃V₂(PO₄)₂O₂F晶粒沿着[002]方向生长并被原位包封在碳壳中, 形成了高度稳定的自组 装结构, 这不仅有利于Na⁺/e⁻的快速迁移, 而且能够有效改善电极材料的循环性能并抑制电压衰减. 作为钠离子电池正极材料, 在0.1C条件 下, Na₃V₂(PO₄)₂O₂F@C的初始放电容量约为127.9 mA h g⁻¹. 在高倍率(20 C)条件下, 容量达88.1 mA h g⁻¹, 2000次循环后容量保持率为 82.1%. 此外, 利用非原位X射线衍射, X射线光电子能谱和恒电流间歇滴定技术, 初步研究了Na₃V₂(PO₄)₂O₂F@C在充放电过程中的反应机 理和Na+迁移机制. 同时, 在Li/Na离子混合电池当中, Na₃V₂(PO₄)₂O₂F@C也表现出了优异的倍率和循环性能. 上述微波辅助低温回流合成 策略为开发高性能电化学储能材料开辟了新的途径.