A Multiscale X-Ray Tomography Study of the Cycled-Induced Degradation in Magnesium-Sulfur Batteries.
A Multiscale X-Ray Tomography Study of the Cycled-Induced Degradation in Magnesium-Sulfur Batteries.
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DOI：
10.1002/smtd.202001193
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发表时间：
2021-03
期刊：
影响因子：
12.4
通讯作者：
W. Du;Zhangxiang Hao;F. Iacoviello;L. Sheng;Shaoliang Guan;Zhenyu Zhang;D. Brett;F. R. Wang;P. Shearing
中科院分区：
文献类型：
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作者：
W. Du;Zhangxiang Hao;F. Iacoviello;L. Sheng;Shaoliang Guan;Zhenyu Zhang;D. Brett;F. R. Wang;P. Shearing
可再充电Mg/S电池由于其高容量和重量能量密度、安全性和低成本构造而具有为一系列应用提供引人注目的电池的潜力。然而，由于技术挑战，包括短循环寿命和缺乏合适的电解质，Mg/S能量存储没有被广泛开发和部署。为了研究Mg/S电池的微观结构退化，对拆除的世伟洛克Mg/S电池（包括石墨烯-硫阴极和super-P隔板）进行多尺度X射线断层扫描（一种固有的非破坏性方法）。3D微观结构可视化和定量首次揭示了硫颗粒的溶解（体积分数从13.5%降至0.7%，表面积从2.91降至1.74 µm2 µm-3）和团聚，以及10次循环后碳粘合剂的致密化。使用断层扫描数据，然后执行基于图像的模拟。结果表明，不溶性多硫化物通过穿梭效应阻碍了Mg 2+的迁移。代表性体积应超过8200 µm3，以代表整体阴极。这项工作阐明了Mg/S电池的性能受到微观结构退化的显着影响，并展示了多尺度和多峰表征如何在开发和优化Mg/S电极设计中发挥不可或缺的作用。
Rechargeable Mg/S batteries have the potential to provide a compelling battery for a range of applications owing to their high capacity and gravimetric energy density, safety, and low-cost construction. However, the Mg/S energy storage is not widely developed and deployed due to technical challenges, which include short cycle lifespan and lack of suitable electrolyte. To study the microstructure degradation of Mg/S batteries, multiscale X-ray tomography, an inherently nondestructive method, is performed on dismantled Swagelok Mg/S cells comprising a graphene-sulfur cathode and a super-P separator. For the first time, 3D microstructure visualization and quantification reveal the dissolution (volume fraction decreases from 13.5% to 0.7%, surface area reduces from 2.91 to 1.74 µm2 µm-3 ) and agglomeration of sulfur particles, and the carbon binder densification after 10 cycles. Using tomography data, the image-based simulations are then performed. The results show that the insoluble polysulfides can inevitably block the Mg2+ transportation via shuttle effect. The representative volume should exceed 8200 µm3 to represent bulk cathode. This work elucidates that the Mg/S cell performance is significantly affected by microstructural degradation, and moreover demonstrates how multiscale and multimodal characterization can play an indispensable role in developing and optimizing the Mg/S electrode design.