CMC negative electrode binder

Core functions (in the negative electrode system)
Dispersant (primary function): In aqueous solution, it dissociates to give pendant –COO⁻ groups. Through electrostatic repulsion and steric hindrance, it uniformly disperses graphite and silicon based particles, preventing agglomeration and sedimentation, and ensuring the homogeneity of the slurry.

Thickening agent (primary function): It significantly increases the viscosity of the slurry and adjusts its rheological properties, making it suitable for high speed coating and helping prevent uneven electrode thickness, pinholes, sagging, bare spots, and other coating defects.

Adhesion promotion and interface stability: –COO⁻/–OH groups form strong hydrogen bonds and ionic bonds with hydroxyl groups on the surfaces of graphite/silicon, enhancing adhesion between particles and between particles and the copper foil. This stabilizes the electrode structure during cycling and mitigates graphite layer delamination and the associated parasitic reactions with the electrolyte.

Electrochemical stability: It exhibits low swelling in the electrolyte and does not significantly decompose within the negative electrode potential range (0.01–1.5 V vs. Li/Li⁺), thereby helping maintain the long term mechanical integrity of the electrode.