LiFePO_(4)电极表面织构化设计与表面润湿性研究  

Surface Texturing Design and Surface Wettability Study of LiFePO_(4)Electrode

作　　者：于凯 王守仁[1] 王英姿[2] YU Kai;WANG Shouren;WANG Yingzi(School of Mechanical Engineering,University of Jinan,Jinan 250022,China;School of Materials Science and Engineering,University of Jinan,Jinan 250022,China)

机构地区：[1]济南大学机械工程学院,济南250022 [2]济南大学材料科学与工程学院,济南250022

出　　处：《表面技术》2025年第4期180-190,共11页Surface Technology

基　　金：国家自然科学基金(52375183);山东省自然科学基金重大基础研究项目(ZR2020ZD06)。

摘　　要：目的提高锂离子电池电极表面的润湿性,改善锂离子扩散动力学,进一步探究织构对电极表面润湿性的影响规律。方法通过超快脉冲激光技术在LiFePO_(4)电极表面制备沟槽织构,借助扫描电子显微镜、非接触式三维光学轮廓仪、接触角测量仪、X射线光电子能谱等测试手段,系统研究了织构对电极表面形貌和润湿性的影响。此外,使用电池测试系统和恒电位仪评估了锂离子电池放电性能和锂离子扩散动力学。结果织构电极表面的润湿性得到了显著改善,接触角降低至7.1°,润湿时间缩短至6 s,扩散面积增加至26.52 mm^(2),润湿过程表现出各向异性。仿真结果证明电解液在织构电极表面处于Wenzel润湿状态,并且拟合得到的接触角方程能较好地解释接触角的变化趋势。织构化电池在0.5 C下的容量保持率从58.4%提高到99.4%,显示出最大的锂离子扩散系数(2.67×10^(-13) cm^(2)/s)。结论织构对电极表面润湿性的改善具有显著效果,并且接触角与织构深径比呈负相关;激光烧蚀增加了电极的表面能,而C=O是提高电极表面亲液性的关键因素;电极材料的进一步润湿改善了锂离子扩散动力学,提高了锂离子电池放电性能,为制备高性能的锂离子电池提供了一定的指导。Lithium-ion batteries are widely used due to their excellent performance.As a commonly used electrode material for lithium-ion batteries,LiFePO_(4)has many advantages such as low cost,high safety and high stability.However,the one-dimensional channel of the olivine structure greatly limits the discharge performance of lithium-ion batteries.In addition,the discharge process of lithium-ion batteres is based on the interface interaction between the electrode and electrolyte,and the wettability directly determines the battery performance.Laser texturing is a method to improve the wettability and discharge performance of lithium-ion batteries,with the advantages of small damage and non-contact.This technology has been partially applied to the battery production process.In this study,micro-grooves were prepared on the surface of the LiFePO_(4)electrode by ultra-fast pulsed laser technique.The influences of micro-texture on the electrode surface morphology and chemical composition were systematically studied by means of scanning electron microscope,X-ray photoelectron spectroscopy,non-contact three-dimensional optical profilometer.The effect of micro-texture on the wettability of the electrode surface was evaluated quantitatively and qualitatively by contact angle measuring instrument and simulation,respectively.In addition,a battery test system and a potentiostat were used to comprehensively evaluate the discharge performance and diffusion kinetics of lithium-ion batteries.The results showed that the wettability of the electrode surface was significantly improved by micro-texture.It was found that the contact angle of electrolyte on the textured electrode surface was inversely related to the texture aspect ratio,which was reduced to 7.1°at most.Furthermore,it was observed from the optical microscope that the diffusion area of the structured electrode surface increased to 26.52 mm^(2) and the wetting time shortened to 6 s.At the same time,the electrolyte spread radially and symmetrically on the original electrode surfa

关 键 词：表面织构 锂离子电池 润湿性 磷酸铁锂 超快脉冲激光 刻蚀形貌 接触角 

分 类 号：TB34[一般工业技术—材料科学与工程]