Analysis of the Deterioration Mechanism of Si Electrode as a Li-Ion Battery Anode Using Raman Microspectroscopy
Analysis of the Deterioration Mechanism of Si Electrode as a Li-Ion Battery Anode Using Raman Microspectroscopy
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DOI：
10.1021/jp5121965
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发表时间：
2015-01
影响因子：
3.7
通讯作者：
M. Shimizu;H. Usui;T. Suzumura;H. Sakaguchi
中科院分区：
文献类型：
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作者：
M. Shimizu;H. Usui;T. Suzumura;H. Sakaguchi
以碳酸丙烯酯（PC）和由1-[（2-甲氧基乙氧基）甲基]-1-甲基哌啶鎓（PP 1 MEM）和双（三氟甲磺酰基）酰胺（TFSA）组成的离子液体作为锂离子电池电解液溶剂，采用气相沉积法制备了厚膜Si电极，研究了其阳极性能。PP 1 MEM-TFSA中的Si电极表现出良好的循环性能，即使在第100次循环时也具有1050 mA h g-1的可逆容量，而PC中的Si电极显示出仅110 mA h g-1的容量。值得注意的是，即使使用相同的Si作为活性材料，仅通过将电解质溶剂改变为离子液体，电极性能也显著增强。循环后的Si阳极的拉曼映射分析进行澄清电极的劣化机制。结果表明，在PC的情况下，循环后结晶硅局部保留在电极中，锂硅合金化和脱溶是导致电极失效的主要原因。
Propylene carbonate (PC) and an ionic liquid consisting of 1-[(2-methoxyethoxy)methyl]-1-methylpiperidinium (PP1MEM) and bis(trifluoromethanesulfonyl)amide (TFSA) were used as electrolyte solvents for Li-ion batteries, and the anode properties of Si electrodes were investigated using a thick film prepared by gas deposition without any binder or conductive additive. The Si electrode in PP1MEM-TFSA exhibited good cycle performance with a reversible capacity of 1050 mA h g–1 even at the 100th cycle, whereas the Si electrode in PC showed a capacity of only 110 mA h g–1. It is noteworthy that the electrode performance was significantly enhanced just by changing the electrolyte solvent to an ionic liquid even with the same Si used as the active material. Raman mapping analyses of the Si anodes after cycling were conducted to clarify the deterioration mechanisms of the electrodes. It was revealed that, in the case of PC, crystalline Si locally remained in the electrode after cycling, and Li–Si alloying and deall...