Defect-Rich Multishelled Fe-Doped Co3O4 Hollow Microspheres with Multiple Spatial Confinements to Facilitate Catalytic Conversion of Polysulfides for High-Performance Li-S Batteries
Defect-Rich Multishelled Fe-Doped Co3O4 Hollow Microspheres with Multiple Spatial Confinements to Facilitate Catalytic Conversion of Polysulfides for High-Performance Li-S Batteries
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DOI：
10.1021/acsami.9b21853
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发表时间：
2020-03-18
影响因子：
9.5
通讯作者：
Wang, Xin
中科院分区：
文献类型：
--
作者：
Wang, Wenjuan;Zhao, Yan;Wang, Xin
在过去的十年里，锂硫(Li-S)电池被认为是新一代电池系统的有前途的替代品。虽然锂-S电池具有较高的理论能量密度(2600Wh kg(-1))和容量(1675mAHg(-1))，但电子和离子传导性差、体积膨胀和硫固定等问题严重阻碍了锂S电池的广泛应用。本论文采用一步水热法和后续热处理的方法合成了富缺陷的多层Co_3O_4掺杂微球。独特的多层结构为锂多硫化物的捕获和缓冲循环过程中的体积变化提供了多重空间限制。此外，通过可控的Fe掺杂设计的富氧缺陷可以为多硫氧化还原反应提供大量的催化中心。由于结构设计和氧缺陷制备的协同作用，硫复合电极具有显著的循环性能，在1℃循环1000次后容量衰减率为0.017%，5 C时的倍率能力为571.3 mAhg(-1)。本工作为设计具有氧缺陷的过渡金属氧化物中空结构提供了一种潜在的途径，也为高性能锂S电池提供了一个新的视角。
Over the past decade, lithium-sulfur (Li-S) batteries have been thought of as promising alternatives for the new generation of battery systems. Although the Li-S batteries possess high-theoretical energy density (2600 Wh kg(-1)) and capacity (1675 mAh g(-1)), the problems of poor electron and ion conduction, volumetric expansion, and sulfur immobilization greatly impede the wide applicability of Li-S batteries. Herein, a defect-rich multishelled Co3O4 microsphere structure doped with Fe was synthesized via a one-step hydrothermal method and subsequent thermal treatment. The unique multishelled structure provides multiple spatial confinements for lithium polysulfides trapping and buffering the volume variation during cycling. Moreover, the rich oxygen defect designed by controlled Fe doping can provide numerous catalytic sites for polysulfide redox reactions. Attributed to the synergistic effect of structural design and oxygen-defect fabrication, the sulfur composite electrode delivers a notable cycle performance, presenting a much lower capacity fading of 0.017% per cycle over 1000 cycles at 1 C and an excellent rate capability of 571.3 mAh g(-1) at 5 C. This work proposes a potential approach for designing a transition metal oxide-based multishelled hollow structure combined with oxygen defect, which also offers a new perspective on high-performance Li-S batteries.