当前位置：
X-MOL 学术
›
ACS Appl. Energy Mater.
›
论文详情
Our official English website, www.x-mol.net, welcomes your
feedback! (Note: you will need to create a separate account there.)
A Multidimensional Operando Study Showing the Importance of the Electrode Macrostructure in Lithium Sulfur Batteries
ACS Applied Energy Materials ( IF 5.4 ) Pub Date : 2020-06-23 00:00:00 , DOI: 10.1021/acsaem.0c01027 Charl J. Jafta 1 , André Hilger 2 , Xiao-Guang Sun 3 , Linxiao Geng 1 , Mengya Li 1 , Sebastian Risse 4 , Ilias Belharouak 1, 5 , Ingo Manke 2
ACS Applied Energy Materials ( IF 5.4 ) Pub Date : 2020-06-23 00:00:00 , DOI: 10.1021/acsaem.0c01027 Charl J. Jafta 1 , André Hilger 2 , Xiao-Guang Sun 3 , Linxiao Geng 1 , Mengya Li 1 , Sebastian Risse 4 , Ilias Belharouak 1, 5 , Ingo Manke 2
Affiliation
|
Lithium sulfur batteries are one of the most promising next-generation energy storage technologies, because of their impressive theoretical energy density, low materials cost, and relative safety. However, incomplete understanding of their underlying operation mechanisms has hindered their further development and commercialization. To gain a better understanding of the operation mechanisms in the lithium sulfur battery, three macroscopically different (woven and nonwoven) and microscopically similar (made from the same carbon fibers) free-standing carbon felts are used as the conductive matrices to show how the macrostructure influences the redox reactions and the electrochemical performance. An operando radiography and simultaneous in situ electrochemical impedance spectroscopy study are performed to highlight the differences of the carbon hosts and how they compare electrochemically in a lithium sulfur battery. The electrochemical results show that the carbon host with a more open structure results in increased capacity as well as a higher diffusion coefficient. The operando radiography shows that the open structures are more conducive to efficient redox reactivity in forming solid sulfur species, mostly in the form of elongated needlelike structures identified as β-S8, near the end of charge, which is corroborated by the impedance data. The data also reveal a “breathing” mechanism, where the polysulfides are pushed to the edges during discharge and pulled back during charge. It is also revealed that the “breathing” process is a limiting factor in the high rate performance. Overall, this study shows that there is a close relationship between the macrostructure of the carbon matrix and the electrochemical performance of the sulfur cathode.
中文翻译：
多维Operando研究显示了锂硫电池中电极宏观结构的重要性
锂硫电池由于其令人印象深刻的理论能量密度，较低的材料成本和相对安全性，因此是最有前途的下一代储能技术之一。但是，对它们的基本运行机制的不完全了解阻碍了它们的进一步发展和商业化。为了更好地理解锂硫电池的工作机理，将三种宏观上不同的（织造的和非织造的）和微观上相似的（由相同的碳纤维制成）的自立式碳毡用作导电基质，以显示宏观结构影响氧化还原反应和电化学性能。进行了操作射线照相和同时原位电化学阻抗谱研究，以突出碳主体之间的差异以及它们如何在锂硫电池中进行电化学比较。电化学结果表明，具有更开放结构的碳主体导致容量增加以及扩散系数更高。射线照相术显示，开放结构更有利于有效的氧化还原反应，形成固态硫，主要呈细长的针状结构形式，称为β-S。如图8所示，在充电即将结束时，这由阻抗数据证实。数据还揭示了一种“呼吸”机制，其中多硫化物在放电过程中被推到边缘，而在充电过程中被拉回。还显示“呼吸”过程是高速率性能的限制因素。总体而言，这项研究表明，碳基体的宏观结构与硫阴极的电化学性能之间存在密切的关系。
更新日期：2020-06-23
中文翻译：
多维Operando研究显示了锂硫电池中电极宏观结构的重要性
锂硫电池由于其令人印象深刻的理论能量密度，较低的材料成本和相对安全性，因此是最有前途的下一代储能技术之一。但是，对它们的基本运行机制的不完全了解阻碍了它们的进一步发展和商业化。为了更好地理解锂硫电池的工作机理，将三种宏观上不同的（织造的和非织造的）和微观上相似的（由相同的碳纤维制成）的自立式碳毡用作导电基质，以显示宏观结构影响氧化还原反应和电化学性能。进行了操作射线照相和同时原位电化学阻抗谱研究，以突出碳主体之间的差异以及它们如何在锂硫电池中进行电化学比较。电化学结果表明，具有更开放结构的碳主体导致容量增加以及扩散系数更高。射线照相术显示，开放结构更有利于有效的氧化还原反应，形成固态硫，主要呈细长的针状结构形式，称为β-S。如图8所示，在充电即将结束时，这由阻抗数据证实。数据还揭示了一种“呼吸”机制，其中多硫化物在放电过程中被推到边缘，而在充电过程中被拉回。还显示“呼吸”过程是高速率性能的限制因素。总体而言，这项研究表明，碳基体的宏观结构与硫阴极的电化学性能之间存在密切的关系。
京公网安备 11010802027423号