随着电化学储能行业的快速扩容和电动车大量普及，对高性能锂电池的需求日益增加。在锂电池中负极材料的性能对电池的性能有很大的影响。因此，研究和开发更好的负极加工工艺是提高锂电池性能的重要途径之一。本文通过研究一种新兴起负极加工工艺—干法电极工艺，对加工时负极复合粉体的粒子演变进行研究，通过仿真分析和实验研究，找到了优化工艺参数的方法，并对优化后的工艺参数进行实验验证。首先，根据实验研究分析粉体粒子的特性，进而探究复合粒子在加工变化时演变机理。采用全干法多辊压延工艺，针对主要成分为氧化亚硅（SiO）和聚四氟乙烯（PTFE）的负极复合粉体，通过理论探究确定SiO和PTFE粒子表现出的特性分别属于内聚区理论（CZM）和粒子粘弹性理论；基于多粒子有限元分析法（MPFEM）和复合粉体粒子特性，对关键的粒子参数如粒子平面断裂应力、高温下松弛曲线等参数进行测定，为辊压模型建立提供依据。其次，针对加工中的关键加工参数确定了粒子仿真模型，并对模型准确性进行了定量验证。建立不同初始孔隙率的仿真模型来模拟复合粉体在多次辊压成膜时，SiO粒子的损伤断裂演变、颗粒重排机理；PTFE树脂粒子的纤维化扩散程度等。并通过敷料层电阻率测量、极片表面轮廓测量等定量实验验证了所构建模型的可靠性。最后，对仿真模型进行压实度分析和应力分析，确定了两种加工参数的优化结果，并对优化结果进行了实验验证。采用控制变量法探究各级辊缝间距和初试粉体孔隙率两种关键参数对极片压实度和表面质量的影响，根据分析结果得到：初始粉体孔隙率最优范围为22.5-26.1%、各级辊缝应根据模型内粒子节点所受的米赛斯应力波段确定，以孔隙率为25.1%的粉体模型为例，如经过七次辊压，各级辊缝压入比例分别为总压入比例的18%、28%、36%、43%、59%、78%、100%。根据得到优化后的工艺参数，进行实验验证，设置两组对照组，对得到的极片测量厚度和压实度，实验组压实度和理论值相吻合，明显好于对照组，压实度为0.72g/cm3满足压实度大于0.70g/cm3，厚度误差3μm小于5μm，满足设定的技术指标。

With the rapid expansion of the electrochemical energy storage industry and the popularity of electric vehicles, the demand for high-performance lithium batteries is increasing. The performance of the anode material in lithium battery has a great impact on the performance of the battery. Therefore, research and development of better negative electrode processing technology is one of the important ways to improve the performance of lithium batteries. In this paper, a new negative electrode processing technology - dry electrode technology, the particle evolution of the negative composite powder during processing was studied. Through simulation analysis and experimental research, a method to optimize the process parameters was found, and the optimized process parameters were verified experimentally.Firstly, based on the experimental study, the characteristics of the powder particles were analyzed, and then the evolution mechanism of the composite particles during processing was explored. The properties of SiO and PTFE particles belong to the cohesive zone theory (CZM) and particle viscoelastic theory, respectively, for the negative composite powders composed of SiO and PTFE by the dry multi-roll calendering process. Based on multi-particle finite element analysis (MPFEM) and particle characteristics of composite powder, the key particle parameters such as particle plane fracture stress and relaxation curve at high temperature were measured, which provided a basis for the establishment of roller model.Secondly, the particle simulation model is determined according to the key machining parameters, and the accuracy of the model is quantitatively verified. A simulation model with different initial porosity was established to simulate the damage and fracture evolution of SiO particles and the mechanism of particle rearrangement during multiple roll forming of composite powders. The degree of fibrosis diffusion of PTFE resin particles. The reliability of the model was verified by quantitative experiments such as dressing layer resistivity measurement and electrode surface profile measurement.Finally, the compactness analysis and stress analysis of the simulation model are carried out to determine the optimization results of two kinds of machining parameters, and the optimization results are verified by experiments. The influence of two key parameters, roll gap spacing at all levels and preliminary powder porosity, on the compactability and surface quality of the polar sheet was explored by using the control variable method. According to the analysis results, the following results were obtained: The optimal range of the initial porosity of the powder is 22.5-26.1%, and the roll gaps at all levels should be determined according to the Mises stress band of the particle nodes in the model. Taking the powder model with a porosity of 25.1% as an example, after seven rolls pressing, The penetration ratio of each roll gap is 18%, 28%, 36%, 43%, 59%, 78% and 100% of the total penetration depth, respectively. According to the optimized process parameters, experimental verification was carried out, and two groups of control group were set. The measured thickness and compactness of the obtained polar sheet were consistent with the theoretical value of the experimental group, and the compactness of the experimental group was obviously better than that of the control group. The compactness of the experimental group was 0.72g/cm3 to meet the requirements of the compactness greater than 0.70g/cm3, and the thickness error of 3μm was less than 5μm, meeting the set technical indicators.