Rolled electrodeposited copper foil with modified surface morphology as anode current collector for high performance lithium-ion batteries

• Published in: Surface & coatings technology 2021-03, Vol.410, p.126881, Article 126881
• Main Authors: Chen, Jingqi, Wang, Xiaogong, Gao, Haitao, Yan, Shu, Chen, Shoudong, Liu, Xianghua, Hu, Xianlei
• Format: Article
• Language: English
• Subjects: Anodes; Charge transfer; Copper; Electric contacts; Electrochemical performances; Lithium; Lithium-ion batteries; Lithium-ion battery; Mechanical properties; Metal foils; Morphology; Rechargeable batteries; Rolled electrodeposited copper foil; Room temperature; Surface morphology modification; Surface roughness
• ISSN: 0257-8972; 1879-3347
• DOI: 10.1016/j.surfcoat.2021.126881

A novel method that taking electrodeposited copper foil as a raw material undergoes asynchronous rolling and surface morphology modification at room temperature was proposed, and the rolled electrodeposited (RE) copper foil with excellent mechanical properties and modified surface morphology was obtained to be used as the anode current collector of high-performance lithium-ion batteries. The surface roughness of RE copper foil (Ra = 1.8 μm) is significantly higher than that of the traditional electrodeposited copper foil (Ra = 0.22 μm) when the thickness is 6 μm. The hilly surface morphology of RE copper foil helps to enhance the interfacial adhesion between current collector and active material, which contributes to the reduction of charge transfer resistance and improvement of specific capacity and rate performance. The mechanical properties of RE copper foil are significantly improved after asynchronous rolling. The excellent mechanical properties of RE copper foil current collector can maintain good electrical contact integrity of electrode active material during lithiation-de-lithiation and significantly improve the cycle life. The discharge capacity of RE electrode is maintained at 329.6 mAh g−1 and exhibits 91.1% capacity retention for 200 cycles at 500 mAg−1, which is much higher than the electrodes with electrodeposited and rolled copper foils as the current collector. •Rolled electrodeposited copper foil can significantly improve the surface roughness and mechanical properties;•The hilly microstructure of rolled electrodeposited copper foil can effectively improve the peel strength of graphite/copper foil.•The hilly microstructure of rolled electrodeposited copper foil can reduce charge transfer resistance and maintain complete electrical contact of the electrode material during the cycle.•The high strength of the rolled electrodeposited copper foil can accommodate the huge volume change and contributes to the better cycle stability.