储能科学与技术 ›› 2020, Vol. 9 ›› Issue (6): 1714-1719.doi: 10.19799/j.cnki.2095-4239.2020.0153

• 储能材料与器件 • 上一篇    下一篇

涂碳铝箔对磷酸铁锂电池性能的影响

李敏1,2(), 相佳媛1(), 杨东辉1, 王羽平1, 陈冬1, 陈建1, 涂江平2   

  1. 1.浙江南都电源动力股份有限公司锂电池研究院,浙江 杭州 311305
    2.浙江大学材料科学与工程学院,浙江 杭州 310027
  • 收稿日期:2020-04-21 修回日期:2020-05-15 出版日期:2020-11-05 发布日期:2020-10-28
  • 通讯作者: 相佳媛 E-mail:limin5632@126.com;xjyzju@aliyun.com
  • 作者简介:李敏(1989—),女,博士,中级工程师,从事锂离子电池体系研究,E-mail:limin5632@126.com
  • 基金资助:
    浙江省博士后科研项目择优资助(zj20180022)

Effect of carbon-coated Al foil on properties of lithium iron phosphate batteries

Min LI1,2(), Jiayuan XIANG1(), Donghui YANG1, Yuping WANG1, Dong CHEN1, Jian CHEN1, Jiangping TU2   

  1. 1.Institute of Lithium ion Battery, Narada Power Source Company Limited, Hangzhou 311305, Zhejiang, China
    2.School of Material Science and Engineering, Zhejiang University, Hangzhou 310027, Zhejiang, China
  • Received:2020-04-21 Revised:2020-05-15 Online:2020-11-05 Published:2020-10-28
  • Contact: Jiayuan XIANG E-mail:limin5632@126.com;xjyzju@aliyun.com

摘要:

为了了解涂碳铝箔对磷酸铁锂电池性能的影响,分别对涂碳铝箔(包括涂炭黑铝箔和涂石墨烯铝箔)和光铝箔进行了形貌表征。扫描电子显微结果显示,涂炭黑铝箔表面没有完全被炭黑颗粒团聚体覆盖,而涂石墨烯铝箔表面则均匀平铺着石墨烯纳米片。之后进一步以3种铝箔为集流体制作了磷酸铁锂电池,来评估其对锂离子电池电化学性能的影响。结果显示,涂碳铝箔和光铝箔所制电池的电化学阻抗谱具有明显差异,涂碳铝箔对电池内阻具有显著的改善作用,光铝箔所制电池的阻抗谱则多一段由铝箔与活性材料界面空隙处的双电层电容产生的容抗弧。存储测试结果表明,使用涂碳铝箔后,电池自放电更小,存储性能有所改善。倍率充放电测试结果显示,涂碳铝箔电池大电流充放电时恒流充入比和放电中值电压更高,电池极化更小,功率性能更好。涂碳铝箔电池的低温性能也更具有竞争优势,其初始放电电压平台更高,放电容量也更高。涂碳铝箔对电池的1 C循环和3 C循环性能也有显著提升。同时,研究发现,涂碳层种类不同,对磷酸铁锂电池性能的提升效果不同:涂石墨烯铝箔在高功率工况下对磷酸铁锂电池性能的提升幅度优于涂炭黑铝箔,原因在于石墨烯片层在沿铝箔表面方向对导电和导热性能的改善优于炭黑涂层。

关键词: 涂碳铝箔, 石墨烯, 磷酸铁锂, 锂离子电池

Abstract:

In this study, the morphology characterization of carbon-coated Al foil and bare Al foil is performed to investigate their effect on the properties of lithium iron phosphate batteries. Scanning electron microscope images show that the surface of carbon black-coated Al foil is partially covered by carbon black particle aggregations, while that of graphene-coated Al foil is uniformly covered by graphene nanosheets. The Al foils are further assembled into lithium iron phosphate batteries to evaluate their effect on the electrochemical performances of lithium-ion batteries. Consequently, the electrochemical impedance spectroscopy curves of the batteries using the carbon-coated and bare Al foils are found to be totally different. The carbon-coated Al foil can reduce the internal resistance of the batteries, while the batteries made by the bare Al foil show an extra curve, which stands for the capacitive reactance attributed to the electrical double-layer capacitance between the Al foil and the active materials. The storage test results indicate that the carbon-coated Al foil can reduce the self-discharge capacity of batteries, leading to a better storage property. The rate charge and discharge tests show that the constant current charge ratio and the discharge median voltage of the batteries using the carbon-coated Al foil at a high-power condition are higher, indicating that the polarization of the batteries is smaller, and the power performance is batter. The batteries with the carbon-coated Al foil have advantages of low-temperature discharge capacity, initial voltage, and better cycling performance at the 1 and 3 C rate. Meanwhile, different kinds of carbon layer show different improvements. The graphene-coated Al foil show a better promotion on the battery performance under high-power conditions due to the improvement of the electron and heat conductivities by graphene nanosheets parallel to the Al foil surface.

Key words: carbon-coated Al foil, graphene, lithium iron phosphate, lithium ion battery

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