Femtosecond laser structuring of graphite anodes for improved lithium-ion batteries: Ablation characteristics and process design
Femtosecond laser structuring of graphite anodes for improved lithium-ion batteries: Ablation characteristics and process design
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DOI：
10.2351/1.5040611
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发表时间：
2018-08-01
影响因子：
2.1
通讯作者：
Huber, Heinz P.
中科院分区：
文献类型：
--
作者：
Habedank, Jan B.;Endres, Joseph;Huber, Heinz P.
锂离子电池因其能量密度高、用途广泛而被广泛应用于储能设备。锂离子电池的关键组成部分是电隔离电极和液体电解质溶液，使离子能够在电极之间传输。激光电极结构是一种很有前途的方法，通过降低电池内阻来增强锂离子电池的大电流能力，因为活性材料与电解质溶液的接触面积更大。在这里描述的工作中，锂离子电池阳极是通过使用具有红外波长的飞秒激光脉冲局部烧蚀涂层的一小部分来构建的。研究了不同工艺参数如激光辐照度和重复频率对烧蚀特性的影响。特别关注烧蚀效率，从而优化工艺设计。通过研究不同粘结剂含量下的烧蚀行为，考虑了电极组成的影响。选择均匀分布的微孔是为了使活性物质的去除降到最低。为了评估结构石墨阳极对锂离子电池电化学性能的影响，制作了测试电池，并在不同电流速率下进行了恒流循环。结果表明，大电流性能得到了改善，这表现为放电容量的增加。(C) 2018年美国激光研究所。
Lithium-ion batteries are widely used as energy storage devices due to their high energy density and versatile applicability. Key components of lithium-ion batteries are electrically isolated electrodes and a liquid electrolyte solution which enables ion transport between the electrodes. Laser structuring of electrodes is a promising approach to enhance the high-current capability of lithium-ion batteries by reducing cell internal resistances, as a larger contact area of the active material with the electrolyte solution is created. In the work described here, lithium-ion battery anodes were structured by locally ablating small fractions of the coating using femtosecond laser pulses with infrared wavelengths. A study on ablation characteristics depending on different process parameters such as laser fluence and repetition rate was performed. Special focus was on the ablation efficiency, enabling an optimized process design. The influence of the electrode composition was taken into account by studying the ablation behavior at a varying binder content. Evenly distributed micro holes were chosen in order to keep active material removal at a minimum. To evaluate the effect of structured graphite anodes on the electrochemical properties of lithium-ion batteries, test cells were manufactured and galvanostatically cycled at different current rates. Results show improvements in high-current performance which is expressed by an increased discharge capacity yield. (C) 2018 Laser Institute of America.