新能源行业的迅速发展带动了锂电铜箔需求的快速增加。同时，动力电池孜孜不倦追求的高能量密度和高安全对锂电铜箔提出了更高的性能要求。为了提升动力电池的容量，锂电铜箔的“极薄化”成为主流发展趋势；然而，为了解决铜箔厚度降低带来的安全隐患，锂电铜箔的高抗拉强度和高延伸率成为提高动力电池安全性的重要保障。为了顺应锂电铜箔“极薄化”和“高强韧化”的发展趋势，本文以6 μm锂电铜箔为研究对象，针对市场上6 μm典型锂电铜箔进行对比分析，建立铜箔性能与结构之间联系，随后开展极薄铜箔生产工艺和热处理工艺优化，以期提高极薄铜箔力学性能，主要结论如下：

（1）研究了不同企业6 μm典型锂电铜箔的微观结构和性能，发现了铜箔光面形貌受钛阴极辊影响，而毛面形貌则与光面形貌和生产工艺联系密切。此时，低粗糙度的阴极辊对获得晶粒细小的铜箔是至关重要的，而晶粒度的减小则有助于铜箔抗拉强度和延伸率的提高。其次，沿(111)生长晶面为主的铜箔具有优异的耐蚀性、高的延伸率和较低的残余应力，显著优于以(220)和(200)为生长晶面的电解铜箔。

（2）考察了电流密度和添加剂对铜箔微观形貌及性能的影响，发现了高电流密度促进晶粒纵向生长，有利于晶粒细化和粗糙度降低，同时提升铜箔延伸率与抗拉强度。在电流密度相同的情况下，添加剂SPS有助于铜箔晶粒致密化，且促进晶粒形貌由尖锥状向丘陵状转变，但力学性能变化不明显，发挥了优异的细晶、整平和光亮作用；胶原蛋白有助于提升铜箔晶粒细化程度和表面平整程度，大幅降低铜箔表面粗糙度，并且能够同时提升铜箔的延伸率及抗拉强度，起到了细晶和整平作用；HEC则促进铜箔晶粒细化和整平，并对铜箔力学性能的提升作用优于SPS和胶原蛋白。

（3）探讨了多元添加剂在电解铜箔过程的作用效能。相比单组元添加剂，三元复合添加剂的作用效能更加显著，获得了抗拉强度为503.85 MPa，延伸率达到4.50%，粗糙度为1.11 μm的高性能电解铜箔，较无添加剂体系所制备的电解铜箔的延伸率提升157%，抗拉强度增加28.35%，粗糙度降低约66.67%，源于添加剂起到了细化晶粒、提升铜箔(111)和(220)晶面占比和抑制铜箔(200)晶面占比作用，显著改善了铜箔力学性能。

（4）分析了时效退火对铜箔性能的影响。经过时效退火，自研铜箔和典型铜箔的延伸率均呈现先增大后降低的变化；而自研铜箔的抗拉强度呈现先降低后小幅增加并趋于稳定的趋势，典型铜箔的抗拉强度呈现出先急剧降低后小幅增加后又降低的变化规律，电导率则呈现先增加后降低的趋势。其中，经过优化退火工艺后，自研铜箔延伸率达到5.30%、抗拉强度达到376.98 MPa；典型铜箔的延伸率达到4.73%，抗拉强度达到505.45 MPa，电导率则升高至106.95 (IACS%)，均较退火前出现了显著变化。

（5）揭示了时效退火过程中同铜箔微观组织的转变行为。经过时效退火，铜箔内部先后出现了退火孪晶与细小晶粒组织，有效释放了电沉积铜箔的内应力，降低达74.80%。随着内应力释放，铜箔的翘曲缺陷得到了消除或明显改善。

The rapid development of the new energy industry has led to the rapid increase of lithium copper foil demand. At the same time, the high energy density and high safety pursued by power batteries put forward higher performance requirements for lithium copper foil. To improve the capacity of power batteries, lithium copper foil "extremely thin" has become the mainstream development trend; However, to solve the safety hazard caused by the reduction of copper foil thickness, the high tensile strength and high elongation of lithium copper foil become an important guarantee to improve the safety of power battery. To comply with the development trend of "ultra-thin" and "high-strength and toughening" lithium copper foil, this paper takes 6μm lithium copper foil as the research object, and compares and analyzes the typical 6μm lithium copper foil in the market, and then builds the relationship between the performance and structure of copper foil, and then carries out the optimization of the production process and heat treatment process of the ultra-thin copper foil, to improve the mechanical properties of the ultra-thin copper foil. The main conclusions are as follows:

(1) The microstructure and properties of 6μm typical lithium copper foil from different enterprises were studied. It was found that the smooth surface morphology of copper foil was affected by the titanium cathode roll, while the rough surface morphology was closely related to the smooth surface morphology and the production process. At this time, the cathode roll with low roughness is very important to obtain copper foil with fine grain size, and the reduction of grain size is conducive to the improvement of tensile strength and elongation of copper foil. Secondly, the copper foil with (111) crystal surface has excellent corrosion resistance, high elongation, and low residual stress, which is significantly superior to the electrolytic copper foil with (220) and (200) crystal surface.

(2) The effects of current density and additives on the microstructure and properties of copper foil were investigated. It was found that high current density promoted the longitudinal growth of grain, was conducive to grain refinement and roughness reduction, and at the same time improved the elongation and tensile strength of copper foil. Under the same current density, the additive SPS contributes to the densification of copper foil grain and promotes the transformation of grain morphology from sharp cone to hill shape, but the mechanical properties do not change significantly, and it plays an excellent fine-grained, smooth, and bright role. Collagen helps to improve the grain refinement degree and surface flatness degree of copper foil, greatly reduces the surface roughness of copper foil, and can improve the elongation and tensile strength of copper foil at the same time, playing the role of fine crystal and leveling. HEC promotes grain refinement and leveling of copper foils and improves the mechanical properties of copper foils better than SPS and collagen.

(3) The effect of multiple additives on electrolytic copper foil is discussed. Compared with the single-component additive, the effect of the ternary composite additive is more significant. The high-performance electrolytic copper foil with a tensile strength of 503.85 MPa, elongation of 4.50%, and roughness of 1.11 μm is obtained. Compared with the electrolytic copper foil prepared without an additive system, the elongation of copper foil is increased by 157% and the tensile strength is increased by 28.35%. The reduction of roughness is about 66.67%, which is due to the effect of additives on refining grain, improving the ratio of (111) and (220) crystal planes and inhibiting the ratio of (200) crystal planes, which significantly improves the mechanical properties of copper foil.

(4) The effect of aging annealing on the properties of copper foil was analyzed. After aging annealing, the elongation of home-made copper foil and typical copper foil increases first and then decreases. The tensile strength of self-made copper foil decreases first and then increases slightly and tends to be stable. The tensile strength of typical copper foil decreases sharply, then increases slightly and then decreases, while the conductivity increases first and then decreases. The elongation and tensile strength of self-developed copper foil reach 5.30% and 376.98 MPa after optimized annealing process. Typical copper foil elongation reaches 4.73%, tensile strength reaches 505.45 MPa, and electrical conductivity increases to 106.95 (IACS%), all of which show significant changes compared with before annealing.

(5) Revealed the transformation behavior of copper foil microstructure during aging annealing. After aging annealing, annealing twins and fine grain structure appeared successively in copper foil, which effectively released the internal stress of electrodeposited copper foil and reduced it by 74.80%. With the release of internal stress, the warping defect of copper foil is eliminated or improved obviously.

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