有色金属工程（有色金属（中英文））

电解铜箔因其优异的导电性和导热性，被广泛用于锂离子电池负极集流体。随着电子和通信技术的发展，市场对更薄、更高性能的铜箔需求增加。为满足这一需求，通常在电解液中添加调控剂，优化铜箔晶粒尺寸和取向，从而提升其力学性能和表面质量。氯离子(Cl~–)是重要添加剂，其浓度显著影响电解铜箔的组织与性能。本文通过调节电解液中NaCl含量改变Cl~–浓度，系统分析了不同浓度下铜箔的结构与性能变化。结果表明：当Cl~–浓度从40 mg·L^–1升至80 mg·L^–1时，铜箔毛面(M面)的(220)_Cu择优取向呈现先增强后减弱的趋势；厚度先增加后减少；M面粗糙度先降低后升高；抗拉强度整体先上升后下降，而延伸率则持续上升。当Cl~–浓度为60 mg·L^–1时，铜箔表面形貌最佳，平均晶粒尺寸为0.66μm，高角度晶界占比最高达88.10%,M面粗糙度最低，抗拉强度达到峰值547 MPa，延伸率为最优值6.03%。

Electrolytic copper foil is extensively utilized as the anode current collector in lithium-ion batteries due to its exceptional electrical and thermal conductivity. With the advancement of electronics and communication technologies,there is an increasing market demand for thinner and higher-performance copper foils. To address this demand,regulatory agents are typically incorporated into the electrolyte to optimize the grain size and orientation of the copper foil,thereby enhancing its mechanical properties and surface quality. Chloride ions(Cl ~–) are important additives,and their concentration significantly affects the microstructure and properties of electrolytic copper foil. This paper aims to deeply explore the influence of Cl ~– concentration on the microstructure and mechanical properties of electrolytic copper foil,providing theoretical basis and technical support for the production of high-performance electrolytic copper foil. First,copper foils were prepared at different Cl ~– concentrations by adjusting the NaCl content in the electrolyte solution,while keeping all electroplating process parameters constant and maintaining consistent types and concentrations of other additives. Then,the structure and preferred orientation of the copper foils were analyzed by X-ray diffraction. The crosssectional morphology of the copper foils was observed by scanning electron microscopy. The grain size and grain boundary characteristics of the copper foils were analyzed by electron backscatter diffraction. The tensile strength and elongation of the copper foils were tested by tensile tests. The morphology and roughness of the matte side(M side,the matte side refers to the side of the copper foil that is close to the electrolyte solution) of the copper foils were characterized by confocal laser scanning microscopy. Finally,the structure and properties of the copper foils prepared under different Cl ~– concentrations were systematically analyzed. The results show that when the Cl ~-concentration increases from 40 mg · L ^–1 to 80 mg · L ^–1,the M side of the copper foils consistently exhibit characteristic diffraction peaks corresponding to face-centered cubic(fcc) copper. However,several key microstructural and mechanical properties exhibit non-monotonic variations with increasing Cl ~– concentration. Specifically,the(220)_Cu preferred orientation of the M side of the copper foil first increases and then decreases,the thickness first increases and then decreases;the roughness of the M side first decreases and then increases;the tensile strength first rises and then falls overall,while the elongation rate continues to increase. When the Cl ~– concentration is 60 mg · L ^–1,the copper foil exhibits the most favorable surface morphology,characterized by minimal edge burrs and superior overall uniformity,the average grain size is 0.66 μm,the proportion of high-angle grain boundaries reaches up to 88.10%,the surface roughness of the M side reaches its minimum value of 2.20 μm,the tensile strength reaches a peak of 574 MPa,and the elongation rate is the optimal value of 6.03%. Notably,the copper foil fabricated through optimized process parameters exhibited superior tensile strength,elongation,and M side roughness compared to literature reports,demonstrating enhanced overall performance and significant technological advancement. In conclusion,this study demonstrates that the precise control of Cl ~– concentration in the electrolyte solution plays a crucial role in enhancing the performance of electrodeposited copper foil. Through systematic research,the optimal addition concentration of Cl ~– was determined to be 60 mg · L ^–1,and the mechanism by which it affects the performance of copper foil by regulating grain size and grain boundary characteristics was revealed. This provides a solid theoretical foundation for the microstructure design of high-performance electrolytic copper foil. Meanwhile,the improved mechanical properties and surface quality contribute to extending the lifespan of lithium-ion batteries and enhancing energy density,which aligns well with the development needs of lightweight,miniaturized,and high-efficiency electronic devices.