As a promising candidate for large-scale electrical energy storage, sodium dual-ion battery (S-DIB) is attracting more and more interest owing to its merits of high voltage as well as the low cost and high abundance of sodium resources. It is highly crucial to develop suitable anode materials for large-scale practical applications of the S-DIBs. In this work, novel hierarchical MoSe₂ yolk-shell spheres constructed of ultrathin nanosheets (designated as MoSe₂ YSs) as anode materials for the S-DIBs are synthesized via the selenization of Mo–glycerate solid spheres and subsequent thermal annealing. The ultrathin feature of nanosheet subunits with expanded (002) interlayer spacing and whole yolk-shell structure not only endow the MoSe₂ YSs with superior reaction kinetics and high capacitive-controlled Na storage, but also provide effective buffer alleviating volume change during Na⁺ intercalation/deintercalation. The assembled S-DIB with the MoSe₂ YSs as the anode and expanded graphite as the cathode delivers impressive discharge capacity of 70.1mAhg⁻¹ at a current density of 0.2Ag⁻¹ after 120 cycles. In addition, the assembled S-DIB exhibits good rate capability with a discharge capacity of 42.9mAhg⁻¹ and high coulombic efficiency beyond 93.5% at a current density of 2.0 Ag⁻¹. Our results suggest that the hierarchical micro/nano-structured MoSe₂ has promising potential as anode materials for high performance S-DIBs.

作为大规模电能存储的有希望的候选者，钠双离子电池（S-DIB）由于其高电压以及钠资源的低成本和高丰度的优点而吸引了越来越多的兴趣。对于S-DIB的大规模实际应用，开发合适的阳极材料至关重要。在这项工作中，通过钼酸甘油酯固溶体的硒化和随后的热退火，合成了由超薄纳米片（指定为MoSe ₂ YSs）作为S-DIB阳极材料的新颖的MoSe ₂卵黄壳球。具有扩展的（002）层间间距和整个蛋壳结构的纳米片亚基的超薄特征不仅赋予MoSe ₂YS具有出色的反应动力学和高电容控制的Na储存量，还提供了有效的缓冲剂，可减轻Na ⁺嵌入/脱嵌过程中的体积变化。组装后的S-DIB以MoSe ₂ YSs为阳极，膨胀石墨为阴极，经过120次循环后，在电流密度为0.2Ag ^-1时，放电容量达70.1mAhg ^-1。此外，组装的S-DIB表现出与42.9mAhg的放电容量良好倍率性能^-1 2.0 Ag构成的电流密度和高库仑效率超过93.5％^-1。我们的结果表明，分层的微/纳米结构的MoSe ₂ 作为高性能S-DIB的阳极材料具有广阔的发展前景。