Surface Characterization of the Carbon Cathode and the Lithium Anode of Li鈥揙2 Batteries Using LiClO4 or LiBOB Salts

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• 作者：Reza Younesi ; Maria Hahlin ; Kristina Edstr枚m
• 刊名：ACS Applied Materials & Interfaces
• 出版年：2013
• 出版时间：February 27, 2013
• 年：2013
• 卷：5
• 期：4
• 页码：1333-1341
• 全文大小：510K
• 年卷期：v.5,no.4(February 27, 2013)
• ISSN：1944-8252

文摘

The surface compositions of a MnO₂ catalyst containing carbon cathode and a Li anode in a Li鈥揙₂ battery were investigated using synchrotron-based photoelectron spectroscopy (PES). Electrolytes comprising LiClO₄ or LiBOB salts in PC or EC:DEC (1:1) solvents were used for this study. Decomposition products from LiClO₄ or LiBOB were observed on the cathode surface when using PC. However, no degradation of LiClO₄ was detected when using EC/DEC. We have demonstrated that both PC and EC/DEC solvents decompose during the cell cycling to form carbonate and ether containing compounds on the surface of the carbon cathode. However, EC/DEC decomposed to a lesser degree compared to PC. PES revealed that a surface layer with a thickness of at least 1鈥? nm remained on the MnO₂ catalyst at the end of the charged state. It was shown that the detachment of Kynar binder influences the surface composition of both the carbon cathode and the Li anode of Li鈥揙₂ cells. The PES results indicated that in the charged state the SEI on the Li anode is composed of PEO, carboxylates, carbonates, and LiClO₄ salt.

Keywords:

lithium-air; Li anode; photoelectron spectroscopy; synchrotron; XPS; oxygen battery; lithium perchlorate; lithium bis(oxalato)borate