Impact of electrochemical cycling on the tensile properties of carbon fibres for structural lithium-ion composite batteries
Impact of electrochemical cycling on the tensile properties of carbon fibres for structural lithium-ion composite batteries
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DOI：
10.1016/j.compscitech.2012.02.006
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发表时间：
2012-04-13
影响因子：
9.1
通讯作者：
Willgert, Markus
中科院分区：
文献类型：
--
作者：
Jacques, Eric;Kjell, Maria H.;Willgert, Markus
碳纤维特别适合用于多功能轻质结构复合材料的设计，这种结构复合材料能够像锂离子电池一样储存能量。在这种情况下，纤维既可以作为高性能的结构增强材料，也可以作为电池电极之一。然而，电化学循环是由锂离子在碳纤维微观结构中的插入和提取组成的，其对碳纤维力学性能的影响尚不清楚。这项研究调查了碳纤维经过多次电化学循环后拉伸性能的变化。用聚丙烯腈基碳纤维制作了一致的碳纤维试件。选择了上浆的T800H和退浆后的IMS65进行了力学性能和电化学性能的比较。在第一次脱锂时，纤维的极限拉伸强度降低了约20%，但在第一次脱锂后，纤维的强度恢复了一些。只要电池容量保持可逆，强度的损失和恢复就不会随循环次数而变化。测量了1000次循环后电池容量的损失，以及锂化纤维的抗张强度的较小损失。这些结果表明，电化学循环不会降低拉伸性能，这似乎依赖于锂离子的插入和提取的量。这两个纤维等级的结果显示出相同的趋势。拉伸刚度不受循环次数的影响。电化学循环后的场发射扫描电子显微镜图像没有显示纤维外表面有任何明显的损伤。(C)2012爱思唯尔有限公司。保留所有权利。
Carbon fibres are particularly well suited for use in a multifunctional lightweight design of a structural composite material able to store energy as a lithium-ion battery. The fibres will in this case act as both a high performance structural reinforcement and one of the battery electrodes. However, the electrochemical cycling consists of insertions and extractions of lithium ions in the microstructure of carbon fibres and its impact on the mechanical performance is unknown. This study investigates the changes in the tensile properties of carbon fibres after they have been subjected to a number of electrochemical cycles. Consistent carbon fibre specimens were manufactured with polyacrylonitrile-based carbon fibres. Sized T800H and desized IMS65 were selected for their mechanical properties and electrochemical capacities. At the first lithiation the ultimate tensile strength of the fibres was reduced of about 20% but after the first delithiation some strength was recovered. The losses and recoveries of strength remained unchanged with the number of cycles as long as the cell capacity remained reversible. Losses in the cell capacity after 1000 cycles were measured together with smaller losses in the tensile strength of the lithiated fibres. These results show that electrochemical cycling does not degrade the tensile properties which seem to depend on the amount of lithium ions inserted and extracted. Both fibre grades exhibited the same trends of results. The tensile stiffness was not affected by the cycling. Field emission scanning electron microscope images taken after electrochemical cycling did not show any obvious damage of the outer surface of the fibres. (c) 2012 Elsevier Ltd. All rights reserved.