Cellulose-Coated Li-Ion Separator for Wettability and Thermal Shrinkage

The patent applies composite materials by combining polyolefin substrate layers with cellulose-based outer layers. The cellulose layers provide hydrophilic properties that improve electrolyte wettability, while the polyolefin layers maintain the shutdown function. This composite structure resolves the contradiction by integrating materials with complementary properties.

The patent applies local quality by differentiating the properties of different layers within the separator structure. The inner polyolefin layers are designed for thermal shutdown functionality, while the outer cellulose layers are designed for electrolyte wettability. Each layer performs its specific function locally, resolving the contradiction between shutdown effect and wettability.

The patent combines polyolefin layers with cellulose-based layers to create a composite separator structure. The cellulose layers provide dimensional stability and resistance to thermal shrinkage, while the polyolefin layers provide shutdown functionality. This composite approach resolves the contradiction between achieving shutdown effect and maintaining shrinking resistance.

The patent changes the thermal parameters of the separator by incorporating cellulose materials with higher thermal stability than polyolefin alone. The cellulose layers raise the overall thermal stability parameter of the separator, enabling it to resist shrinkage at elevated temperatures while the polyolefin layers still provide shutdown at lower temperatures.

The patent uses composite materials combining polyolefin and cellulose layers. The cellulose layers provide high-temperature dimensional stability, while the polyolefin layers maintain ease of manufacturing through established processes. The composite structure achieves both goals by integrating materials that excel in different properties.

The patent segments the separator into multiple functional layers with distinct roles. The polyolefin layers are manufactured using simple, established processes, while the cellulose layers are added to provide thermal stability. This segmentation allows each layer to be optimized for its specific function while maintaining overall manufacturing feasibility.

The patent uses commercially available cellulose-based materials and standard lamination processes instead of complex FBI membrane fabrication. The cellulose layers can be applied using simple coating or lamination techniques, avoiding the lengthy and complex fabrication steps required for porous FBI membranes while achieving similar or better performance.

The patent uses cellulose as an intermediary material that provides both wettability improvement and thermal stability without requiring complex fabrication processes. The cellulose layers act as a mediator between the polyolefin substrate and the electrolyte, providing hydrophilic pathways for ion transport while maintaining thermal stability through standard manufacturing processes.