CNT Negative Electrode Composition for Binder Migration Control

The patent changes the chemical composition parameters of the binder system by introducing a specific ratio of carboxymethyl cellulose (1-5 parts by weight) and styrene-butadiene rubber (95-99.9 parts by weight). This compositional parameter change modifies the binder's rheological properties to prevent migration during drying while maintaining adhesion. The SBR component provides strong adhesive properties that compensate for any binder loss during the drying process.

The patent uses a composite binder system combining carboxymethyl cellulose (CMC) and styrene-butadiene rubber (SBR) in specific ratios. CMC provides water solubility and film-forming properties, while SBR provides elastic adhesion and crack resistance. This composite approach creates a binder that maintains uniform distribution during drying and ensures strong, flexible adhesion between the active material layer and current collector.

The patent changes the binder composition rather than increasing quantity. By using SBR (95-99.9 parts by weight) with high inherent adhesion properties, effective adhesion is achieved with minimal binder content (1-10 parts by weight per 100 parts graphite). This prevents binder aggregation and maintains uniform electrode structure and conductivity.

The patent uses small amounts of CMC (1-5 parts by weight) as a sacrificial component that provides water solubility and processing benefits but decomposes during drying. This allows the binder system to achieve uniform distribution and strong adhesion without requiring large quantities of permanent binder that would compromise electrode uniformity and conductivity.