In the preparation of lithium-ion battery electrode slurries, the choice of dispersant directly affects electrode quality and battery performance. Polyvinylpyrrolidone (PVP), as a non-ionic polymeric dispersant, plays a crucial role in dispersing and stabilizing slurry systems due to its unique molecular structure. Its molecular chain combines polar lactam groups with lipophilic long chains, allowing it to adsorb onto the surfaces of active materials such as lithium iron phosphate and ternary materials, as well as conductive agents such as carbon nanotubes and graphene. Through steric hindrance, it forms a physical barrier, counteracting van der Waals forces between particles, inhibiting aggregation and sedimentation, and ensuring long-term uniformity and stability of the solid-liquid system.

PVP's dispersion mechanism has a wide range of applicability, applicable to various slurry systems, including non-aqueous and aqueous phases such as NMP. In oily systems, its pyrrolidone ring exhibits good solvent compatibility, effectively wetting particles, deagglomerating and stabilizing agglomerated powders. For easily entangled nano-conductive agents such as carbon nanotubes, PVP tightly adsorbs through π-π conjugation, reducing entanglement rates and facilitating the construction of a continuous, interconnected three-dimensional conductive network. This dispersing ability reduces slurry viscosity, improving both solids content and rheological properties.

The process optimization effects of PVP are significant. The low-viscosity, highly stable slurry is easier to mix and transport, improving the continuity and uniformity of the coating process, controlling electrode thickness deviation within the micrometer range, and reducing localized polarization caused by uneven thickness. Simultaneously, PVP completely decomposes without residue during high-temperature heat treatment, preventing impurities from adversely affecting electrode purity and interfacial reactions. Its auxiliary bonding properties also enhance the adhesion between the active material and the current collector, reducing the possibility of electrode powdering and cracking, and improving the integrity of the electrode structure.

From a battery performance perspective, the application of PVP has a positive impact on improving electrochemical performance. The optimized dispersion allows for a more uniform mixing and distribution of the active material and conductive agent, fully utilizing the functional value of each component and reducing performance loss due to particle agglomeration. The uniform conductive network promotes rapid lithium-ion and electron transport, allowing for more complete reactions during charging and discharging, and mitigating polarization. Meanwhile, the stable electrode structure benefits from the dispersion and assisted bonding effects of PVP, maintaining structural integrity during long-term cycling, reducing active material shedding and conductive path breakage, and extending battery life. Furthermore, the mild properties of PVP do not adversely affect the electrode interface, helping to maintain a stable reaction between the electrolyte and the electrode, thus improving battery safety and reliability. As the new energy industry's requirements for battery energy density and lifespan gradually increase, the application value of PVP in high-end electrode manufacturing is becoming increasingly prominent.

PENGFEI is a company dedicated to the research, production, and sales of 2-pyrrolidone (2-P), N-vinylpyrrolidone (NVP), and polyvinylpyrrolidone (PVP)