储能科学与技术 ›› 2021, Vol. 10 ›› Issue (4): 1311-1316.doi: 10.19799/j.cnki.2095-4239.2021.0081

• 储能材料与器件 • 上一篇    下一篇

锂离子电池用无溶剂干法电极的制备及其性能研究

郭德超1(), 郭义敏1, 张啟文1, 慈祥云1, 何凤荣1,2()   

  1. 1.东莞东阳光科研发有限公司，广东 东莞 523871
    2.四川大学化学工程学院，四川 成都 610065
  • 收稿日期:2021-03-05 修回日期:2021-04-28 出版日期:2021-07-05 发布日期:2021-06-25
  • 通讯作者: 何凤荣 E-mail:guodechao@hec.cn;hefengrong@hec.cn
  • 作者简介:郭德超（1987—），男，硕士，工程师，研究方向为电化学储能器件及其关键材料，E-mail：guodechao@hec.cn。

Preparation and characterization of solvent-free dry electrodes for lithium ion batteries

Dechao GUO1(), Yimin GUO1, Qiwen ZHANG1, Xiangyun CI1, Fengrong HE1,2()   

  1. 1.Dongguan Dongyangguang Research and Development Co. , Ltd. , Dongguan 523871, Guangdong, China
    2.School of Chemical Engineering, SiChuan University, Chengdu 610065, Sichuan, China
  • Received:2021-03-05 Revised:2021-04-28 Online:2021-07-05 Published:2021-06-25
  • Contact: Fengrong HE E-mail:guodechao@hec.cn;hefengrong@hec.cn

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摘要：

采用无溶剂电极制备技术成功制备了锂离子电池用LiNi0.8Co0.1Mn0.1O2干法电极片，采用扫描电子显微镜(SEM)和X射线能谱仪(EDS)对干法电极片的形貌和元素分布进行了分析测试，通过倍率充放电、交流阻抗、循环充放电等测试手段研究了干法电极片的电化学性能。结果表明：纤维状PTFE广泛地分布在LiNi0.8Co0.1Mn0.1O2活性物质颗粒的周围，在干法电极内部形成了一个致密、完整、柔性的网状黏结剂结构；电极循环500圈后，容量保持率为94.89%，循环性能明显优于传统的湿法涂布电极。500圈循环后的电极片内部仍保持着稳定的网状黏结剂结构，LiNi0.8Co0.1Mn0.1O2活性物质颗粒表面的裂隙显著少于湿法涂布电极，表明由PTFE纤维构成的三维网络结构能够有效地改善电极片的抗劣化性能。由于干法电极技术在制备过程中不使用任何溶剂，有减少原材料、降低能耗、环境友好的优点，且该技术支持制备厚电极进而能够提高锂离子电池的能量密度，具有较强的实际应用价值。

关键词: 无溶剂干法电极, 自支撑膜, PTFE纤维化, 锂离子电池

Abstract:

LiNi0.8Co0.1Mn0.1O2 dry electrodes for lithium-ion batteries were prepared using a solvent-free electrode preparation technology. The morphology and elemental distribution of the dry electrodes were analyzed using a scanning electron microscope and an X-ray energy spectrometer (EDS). The electrochemical performance of LiNi0.8Co0.1Mn0.1O2 dry electrodes were characterized by the rate of charge/discharge, electrochemical impedance spectroscopy, and cycle charge/discharge. The results show that in the dry electrodes, PTFE fibers are widely distributed around the LiNi0.8Co0.1Mn0.1O2 particles, which form a dense, complete, and flexible net-like binding structure. Batteries containing the dry electrodes delivered an excellent capacity retention of 94.89% for more than 500 cycles, which is much greater than that of traditional wet-coated electrodes. Inside the dry electrodes after 500 cycles, a stable net-like binding structure was maintained, and there were significantly less cracks on the surface of the LiNi0.8Co0.1Mn0.1O2 particles than on the wet-coated electrodes. These results indicate that the three-dimensional net-like binding structure formed by PTFE fibers can effectively improve the anti-deterioration performance of the electrodes. No solvents were used in the preparation of the dry electrodes, which can reduce the amount of raw materials and energy consumption, and thus be environmentally friendly. The solvent-free electrode preparation technology provides many practical applications in the preparation of thick electrodes to i ncrease the energy density of lithium-ion batteries.

Key words: solvent-free dry electrodes, free-standing films, PTFE fibration, lithium ion batteries

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