This technology involves the synthesis of polyacrylamide-based anionic and cationic polymer binders via radical polymerization. These binders utilize Coulombic interactions (electrostatic attraction) and hydrogen bonding to suppress the swelling of high-capacity anode active materials, such as silicon, during charge and discharge cycles.
High-capacity anode materials like silicon can expand by up to 300% during charge and discharge, leading to mechanical degradation of the electrode and detachment of the active material. This process causes continuous electrolyte consumption and instability in the SEI layer, resulting in a rapid decline in battery capacity and lifespan.
The technology involves preparing anionic and cationic polymers by heating a mixture of an initiator, acrylamide, and sulfonic or ammonium monomers in a phosphate buffer solution under a nitrogen atmosphere. These two polymers are then blended to form a robust, reversible network of Coulombic interactions and hydrogen bonds. Applicable to silicon/silicon oxide composite anodes, high-capacity fast-charging cells, and aqueous electrode slurry processes, this binder absorbs volume expansion stress through its self-healing effect. Its simple synthesis process also facilitates easy transition to mass production.
N/A
