Negative Electrode Binder Composition for Low Resistance and Adhesion

The patent employs a composite binder system comprising multiple polymer components including carboxymethyl cellulose (CMC), styrene-butadiene rubber (SBR), and conductive polymers. This composite approach synergistically combines the adhesion properties of CMC, the flexibility and bonding strength of SBR, and the electrical conductivity of conductive polymers, thereby achieving superior adhesion to current collector while maintaining manageable manufacturing complexity through established coating processes.

The patent optimizes specific parameter ranges for binder composition (e.g., CMC content at 1-5 wt%, SBR content at 2-8 wt%, conductive polymer content at 0.5-3 wt%) and processing conditions (pH value, drying temperature, coating thickness) to achieve optimal adhesion. By controlling these parameters within defined ranges, the patent balances adhesion improvement with manufacturing feasibility, avoiding excessive complexity while achieving the desired strength enhancement.

The patent incorporates conductive polymers and carbon-based materials that simultaneously serve dual functions: enhancing electrical conductivity to reduce plate resistance and providing additional bonding sites for improved adhesion to the current collector. This multi-functional approach allows the electrode composition to achieve both low resistance and high adhesion without requiring separate optimization of conflicting parameters.

The composite binder system including conductive polymers creates a network that provides both electrical pathways for low resistance and mechanical bonding for high adhesion. The conductive polymer matrix interconnects active material particles while anchoring to the current collector, thereby simultaneously addressing electrical conductivity and adhesion requirements without compromise.