The drying rate would significantly affect the quality of the composite electrode after solidification. In order to clarify the underlying effect mechanism of ingredient heterogeneity in the electrode caused by the drying process on the mechanical integrity of lithium secondary batteries in service, an integrated analysis approach is developed to determine the mechanical properties and lithium diffusion-induced stress of the composite electrode with gradient distributed binder and conductive agent. A faster solidification is found to broaden the inhomogeneous extent of inactive components in the electrode coating across its thickness, markedly. As a result, it will not only enlarge the tensile stress in the brittle electrode upon electrochemical operation due to the increased effective modulus of composite near the surface, but will also impair the interfacial strength between the active layer and current collector. Moreover, a two-stage drying protocol (initially fast, followed by slow evaporation of solvent) is found to be greatly beneficial to boosting the resistance to cohesion failure and surface damage of the composite electrode, and the optimized processing parameters are proposed to obtain a robust production with high efficiency.

干燥速率将显着影响固化后复合电极的质量。为了阐明干燥过程中电极中成分异质性对使用中的锂二次电池的机械完整性的潜在影响机理，开发了一种综合分析方法来确定复合材料的机械性能和锂扩散引起的应力带有梯度分布的粘合剂和导电剂的电极。发现更快的固化显着地扩大了电极涂层中非活性成分的不均匀程度。结果，由于在表面附近复合材料的有效模量增加，不仅在电化学操作时会增加脆性电极中的拉应力，但是也会削弱有源层和集电器之间的界面强度。此外，发现两阶段干燥方案（最初是快速的，然后是缓慢的溶剂蒸发）对于提高复合电极的抗内聚破坏性和表面损伤的抵抗力非常有利，并提出了优化的工艺参数以获得一种高效生产。