Negative Electrode Composite Binder for High-Density Battery Cycling

The patent employs a composite binder system of cellulose fiber and CMC that enables the negative electrode to achieve high energy density while maintaining excellent cyclability and electric resistance characteristics. The cellulose fiber provides structural framework that accommodates volume changes during cycling, while CMC ensures good adhesion and ion transport. This composite structure allows maximization of active material content (improving energy density) without compromising the electrode's structural integrity or electrical performance over cycles.

The patent applies different binder materials at different locations and functions within the negative electrode structure. Cellulose fiber primarily provides mechanical support and structural stability, while CMC focuses on surface adhesion to electrode particles and ion conductivity at the electrode-electrolyte interface. This localized functional differentiation allows the electrode to simultaneously achieve high energy density through optimized active material packing and superior cyclability through targeted binder functions at critical locations.