SnSe2 /FeSe2 Nanocubes Capsulated in Nitrogen-Doped Carbon Realizing Stable Sodium-Ion Storage at Ultrahigh Rate.
SnSe2 /FeSe2 Nanocubes Capsulated in Nitrogen-Doped Carbon Realizing Stable Sodium-Ion Storage at Ultrahigh Rate.
复制标题
DOI：
10.1002/smtd.202100437
复制
发表时间：
2021-08
期刊：
影响因子：
12.4
通讯作者：
Xiaoyu Gao;Yixi Kuai;Zhixin Xu;Yongjie Cao;Nan Wang;S. Hirano;Yanna Nuli;Jiulin Wang;Jun Yang
中科院分区：
文献类型：
--
作者：
Xiaoyu Gao;Yixi Kuai;Zhixin Xu;Yongjie Cao;Nan Wang;S. Hirano;Yanna Nuli;Jiulin Wang;Jun Yang
近年来，金属硒化物作为钠离子电池（SIB）的负极材料，因其容量大、导电性好、对环境友好而受到越来越多的关注。然而，金属硒化物的应用受到巨大体积变化的阻碍，这导致电极结构破坏以及随之而来的循环稳定性和倍率性能下降。为了克服上述障碍，本文通过简单的共沉淀方法，然后通过聚多巴胺包裹和一步硒化/碳化过程来制备封装在氮掺杂碳（SFS@NC）中的SnSe 2/FeSe 2纳米立方体。SFS@NC最显著的特点是在高电流密度下的超稳定性，同时提供大容量。双硒化物组分和核-壳结构的协同效应减轻了体积效应，抑制了纳米颗粒的团聚，并进一步提高了电导率。所制备的SFS@NC纳米立方体在6 A g-1下1200次循环后呈现出408.1 mAh g-1的高容量，对应于85.3%的保留率，并且可以在20 A g-1的极高电流密度下实现345.0 mAh g-1的容量。SFS@NC的优异性能为今后的材料结构设计策略提供了启示，促进了SIB的进一步发展和应用。
Metal selenides have attracted increasing attention recently as anodes for sodium-ion batteries (SIBs) because of their large capacities, high electric conductivity, as well as environmental benignity. However, the application of metal selenides is hindered by the huge volume variation, which causes electrode structure devastation and the consequent degrading cycling stability and rate capability. To overcome the aforementioned obstacles, herein, SnSe2 /FeSe2 nanocubes capsulated in nitrogen-doped carbon (SFS@NC) are fabricated via a facile co-precipitation method, followed by poly-dopamine wrapping and one-step selenization/carbonization procedure. The most remarkable feature of SFS@NC is the ultra-stability under high current density while delivering a large capacity. The synergistic effect of dual selenide components and core-shell architecture mitigates the volume effect, alleviates the agglomeration of nanoparticles, and further improves the electric conductivity. The as-prepared SFS@NC nanocubes present a high capacity of 408.1 mAh g-1 after 1200 cycles at 6 A g-1 , corresponding to an 85.3% retention, and can achieve a capacity of 345.0 mAh g-1 at an extremely high current density of 20 A g-1 . The outstanding performance of SFS@NC may provide a hint to future material structure design strategy, and promote further developments and applications of SIBs.