Belgian-based Solvay speciality chemicals showed its range of Solef® polyvinylidene fluoride (PVDF) materials for the battery market including its new PVDF technology for solvent and water based separator coatings for high-energy, high-safety and high-sustainability lithium-ion batteries at Interbattery in Seoul Korea last month.
With Korean makers at the heart of battery development for the EV market, Solvay is the only PVDF supplier that uses both emulsion and suspension polymerization technology, thereby offering the industry the broadest range of high-performance binders and separator coating materials.
Solvay’s new Solef® 75130 PVDF offer for use with today’s most common ceramic coatings exhibits excellent cohesion within the ceramic coating particles as well as safe adhesion between the ceramic particles and the separator substrate, which is key in obtaining a more effective and long-term high-energy battery performance. In addition, it provides good lamination performance with electrodes, helps to minimize the internal resistance of the separator, and shows outstanding pore forming capabilities for separators with high ionic conductivity in Li-ion batteries. Depending on the design of the separator, it can be used as its main component or just as a thin coating layer.
Moreover, Solef® PVDF aqueous dispersions can eliminate the need for organic solvents, thus reducing the carbon footprint of battery manufacturers as well as their solvent recycling costs. In addition, due to its good wettability in electrolytes and its ease of processing at lower temperatures, it also results in a more sustainable process further characterized by lower energy consumption.
Best talks to Prakash Raman, Global Business Development Manager LI Ion Battery, Solvay Specialty Polymer
Q1) What advantages does Solef® PVDF bring to the industry?
A1) The battery industry continues to look for materials that enhances the safety and performance of the batteries, technology of binders is one of the critical requirement in the technology evolution of the batteries. The primary function of Solef® PVDF binder is to provide adhesion to the collectors and ensure cohesion of the particles within the electrode remains high during the operational life of the battery.
Solef® PVDF is partially fluorinated fluro polymer known to improve the chemical resistance, versus hydrogenated polymers, that is needed in the harsh internal environment of a lithium based cell. Any material that is staying in the environment of permanent Chemical Redox reaction during charge and discharge of the cells, might suffer from degradation and see its adhesion properties degrading through the time. The chemical stability of Solef® PVDF significantly reduces this risk and increase the safe operation of batteries. Solef® PVDF Chemical stability of the binder and high adhesion enable to reduce the binder content and consequently increase the capacity and cyclability of Li batteries.
Q2) The company claims Solef® PVDF can help meet the needs of users when used as a cathode binder material. How does it do this?
A2 Solef® PVDF has a higher electrochemical stability than most of polymer binders. That electrochemical stability is required to withstand the 3,7V minimum voltage that is encountered in Lithium ion batteries. The Technology roadmap of LIB covers the progressive increase of the cell voltage to increase the capacity. High electrochemical stability of binders