Comparative study on lithium borates as corrosion inhibitors of aluminum current collector in. lithium bis(fluorosulfonyl)imide electrolytes
Comparative study on lithium borates as corrosion inhibitors of aluminum current collector in. lithium bis(fluorosulfonyl)imide electrolytes
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DOI：
10.1016/j.jpowsour.2015.07.052
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发表时间：
2015-11-20
影响因子：
9.2
通讯作者：
Lee, Hochun
中科院分区：
文献类型：
--
作者：
Park, Kisung;Yu, Sunghun;Lee, Hochun
双（氟磺酰基）亚胺锂（LiFSI）是一种很有前途的盐，有可能克服当前锂离子电池（LIB）中六氟磷酸锂（LiPF6）的局限性。然而，铝（Al）腐蚀问题是LiFSI广泛使用的主要瓶颈。本研究研究硼酸锂盐作为 LiFSI 电解质中的铝腐蚀抑制剂。通过对四氟硼酸锂（LiBF4）、二草酸硼酸锂（LiBOB）和二氟草酸硼酸锂（LiDFOB）与LiPF6的系统比较，发现添加剂的缓蚀能力按以下顺序排列：LiDFOB>LiBF4，近似于LiPF6>LiBOB。尤其是LiDFOB的抑制效果突出； Al 在 0.8 M LiFSI + 0.2 M LiDFOB 碳酸亚乙酯 (EC) 基电解液中的阳极行为与无腐蚀的 1 M LiPF6 溶液相当。 X 射线光电子能谱 (XPS) 测量证明，LiDFOB 的优异抑制能力归因于形成了由 Al-F、Al2O3 和 B-O 物质组成的钝化层。采用 0.8 M LiFSI + 0.2 M LiDFOB 电解质的 LiCoO2/石墨电池的倍率性能与采用 1 M LiPF6 溶液的电池相当，而采用 0.8 M LiFSI 溶液但不含 LiDFOB 的电池由于严重的铝腐蚀而导致功率性能较差。 (C) 2015 Elsevier B.V. 保留所有权利。
Lithium bis(fluorosulfonyl)imide (LiFSI) is a promising salt that can possibly overcome the limitations of lithium hexafluorophosphate (LiPF6) in current Li-ion batteries (LIBs). Aluminum (Al) corrosion issue, however, is a major bottleneck for the wide use of LiFSI. This study investigates lithium borate salts as Al corrosion inhibitors in LiFSI electrolytes. Through a systematic comparison among lithium tetrafluoroborate (LiBF4), lithium bis(oxalato)borate (LiBOB), and lithium difluoro(oxalato)borate (LiDFOB), and LiPF6, the inhibition ability of the additives is revealed to be in the following order: LiDFOB > LiBF4 approximate to LiPF6 > LiBOB. In particular, the inhibition effect of LiDFOB is outstanding; the anodic behavior of Al in 0.8 M LiFSI + 0.2 M LiDFOB ethylene carbonate (EC)-based electrolyte is comparable to that of corrosion-free 1 M LiPF6 solution. The superior inhibition ability of LiDFOB is attributed to the formation of a passive layer composed of Al-F, Al2O3, and B-O species, as evidenced by X-ray photoelectron spectroscopy (XPS) measurements. A LiCoO2/graphite cell with 0.8 M LiFSI + 0.2 M LiDFOB electrolyte exhibits a rate capability comparable to a cell with 1 M LiPF6 solution, whereas a cell with 0.8 M LiFSI solution without LiDFOB suffers from poor power performance resulting from severe Al corrosion. (C) 2015 Elsevier B.V. All rights reserved.