Conductive Polymer Binders for Lithium Ion Battery Electrodes

The patent employs composite binder materials that combine conventional stable binders (PVdF, CMC, SBR) with conductive polymers (PEDOT, polypyrrole, polythiophene) to achieve both electrochemical stability and high electrical conductivity. The composite structure allows the stable binder to provide reliability while the conductive polymer component provides the necessary electrical and ionic conductivity pathways.

The patent modifies the chemical and physical parameters of binder materials by introducing conjugated π-electron systems through polymerization of aromatic compounds (aniline, pyrrole, thiophene). This fundamental parameter change transforms the electrical conductivity of the binder from insulating to conductive while maintaining electrochemical stability through proper polymer structure design.

The patent extracts the conductive function from separate additive components and integrates it directly into the binder material itself. By making the binder inherently conductive through conjugated polymer structures, the need for additional conductive additives (like carbon black or metal particles) is reduced or eliminated, thereby increasing the proportion of active material in the electrode composition.

The conductive polymer binder serves multiple functions simultaneously: it provides electrochemical stability, ensures mechanical adhesion of active material particles, enables electrical conductivity, and facilitates ion transport. This multi-functionality replaces what would traditionally require separate components (binder + conductive additive + adhesion promoter), increasing active material content.