Energy Storage Science and Technology ›› 2020, Vol. 9 ›› Issue (6): 1714-1719.doi: 10.19799/j.cnki.2095-4239.2020.0153

• Energy Storage Materials and Devices • Previous Articles     Next Articles

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

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

CLC Number: