Wang Jinkai, Zhu Lei, Li Fang, Yao Tianhao, Liu Ting, Cheng Yonghong, Yin Zongyou, Wang Hongkang
State Key Lab of Electrical Insulation and Power Equipment, Center of Nanomaterials for Renewable Energy (CNRE), School of Electrical Engineering, Xi'an Jiaotong University, Xi'an, 710049, China.
Research School of Chemistry, Australian National University, Canberra, ACT, 2601, Australia.
Small. 2020 Aug;16(33):e2002487. doi: 10.1002/smll.202002487. Epub 2020 Jul 12.
Sodium-ion batteries (SIBs) have been recognized as the promising alternatives to lithium-ion batteries for large-scale applications owing to their abundant sodium resource. Currently, one significant challenge for SIBs is to explore feasible anodes with high specific capacity and reversible pulverization-free Na insertion/extraction. Herein, a facile co-engineering on polymorph phases and cavity structures is developed based on CoMo-glycerate by scalable solvothermal sulfidation. The optimized strategy enables the construction of CoMoO S with synergized partially sulfidized amorphous phase and yolk-shell confined cavity. When developed as anodes for SIBs, such CoMoO S electrodes deliver a high reversible capacity of 479.4 mA h g at 200 mA g after 100 cycles and a high rate capacity of 435.2 mA h g even at 2000 mA g , demonstrating superior capacity and rate capability. These are attributed to the unique dual merits of the anodes, that is, the elastic bountiful reaction pathways favored by the sulfidation-induced amorphous phase and the sodiation/desodiation accommodatable space benefits from the yolk-shell cavity. Such yolk-shell nano-battery materials are merited with co-tunable phases and structures, facile scalable fabrication, and excellent capacity and rate capability in sodium storage. This provides an opportunity to develop advanced practical electrochemical sodium storage in the future.
钠离子电池（SIBs）因其丰富的钠资源而被认为是大规模应用中锂离子电池的有前途的替代品。目前，SIBs面临的一个重大挑战是探索具有高比容量和可逆无粉化钠嵌入/脱出的可行阳极。在此，基于CoMo-甘油酸盐通过可扩展的溶剂热硫化开发了一种多晶型相和腔结构的简便协同工程。优化后的策略能够构建具有协同部分硫化非晶相和蛋黄壳受限腔的CoMoO S。当用作SIBs的阳极时，这种CoMoO S电极在100次循环后在200 mA g下具有479.4 mA h g的高可逆容量，甚至在2000 mA g下也具有435.2 mA h g的高倍率容量，展示出卓越的容量和倍率性能。这些归因于阳极的独特双重优点，即硫化诱导的非晶相有利于弹性丰富的反应途径，以及蛋黄壳腔带来的钠化/脱钠可容纳空间。这种蛋黄壳纳米电池材料具有可共同调节的相和结构、简便的可扩展制造以及优异的钠存储容量和倍率性能。这为未来开发先进的实用电化学钠存储提供了机会。
