Specialty Polymers for Li-Ion Battery Cells

Lithium-ion-battery-layers

Solvay offers a portfolio of specialty polymers formulated to provide Lithium-Ion (Li-Ion) batteries with long-term durability, chemical and electrochemical resistance and high-temperature performance to enhance sustainability, increase battery energy density, streamline manufacturing and reduce environmental footprint. Specifically, our cost-effective, high-performing plastics are manufactured with superior properties increase adhesion, cycle life and processability in cathode binders, and increase strength and chemical resistance in separators and cell gaskets.

Today’s Li-Ion batteries must deliver increased energy in more compact spaces. Accordingly, OEMs demand components with high voltage tolerance, high temperature compatibility, extended cycle life and simplified processing for outstanding performance, manufacturing and storage compatibility. Additionally, the rapid expansion of the Li-Ion battery industry, OEMs simultaneously require innovative solutions and materials with eco-friendly processing methods. Our polymerization technologies deliver a family of specialty polymers that meet and exceed these lithium battery performance and processing expectations. For example, Solvay continues to lead the battery market in environmentally friendly solutions with the development of the first commercialized water-based Polyvinylidene Fluoride (PVDF) for separator coatings. 

 

Binders and Separators

Improved Battery Energy Density

Modern batteries require higher energy densities to deliver optimum performance in downsized, more efficient systems and storage. Solvay’s polymerization technology facilitates chemical modification to improve the adhesiveness and flexibility of cathode binders used in high density electrodes. The unmatched cohesion and adhesion of our industry-leading PVDF binders allows manufacturers to utilize less binder content, which enables miniaturization and enhances performance and enhances performance. Specifically, Solef® PVDF is a partially fluorinated polymer with excellent chemical properties and tremendous temperature tolerance to provide unparalleled adhesion and anti-gelation and ensure maximum efficiency in the production and performance of an array of Li-Ion batteries. 

Solef-pvdf-vs-hydrogenated-polymers-properties-for-batteries-01

Adhesion is a key property which determines final performance of batteries, especially in the long term. A good binder guarantees the homogeneous dispersion of active materials and conductive carbon together with stable bonding to the metallic collector.

Adhesion comparison

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Enhanced Durability and Stability

Reliable Li-Ion batteries require highly adhesive binders with significant flexibility and a dependable interface between the separator and the electrodes to ensure long-term performance. The excellent adhesion of Solvay’s high-quality polymers for battery binders offers continued stability over extended periods. Additionally, our engineers coat the separators with additional layers of PVDF which increases wettability and enables high lamination strength within the cell. Solef® PVDF is available in several modified grades used in both high-performance binders and adhesive separator coatings to increase cycle life by limiting the leakage of electrolytes in modern Li-Ion batteries.

 

Unmatched Versatility and Innovation

Solvay’s Solef® PVDF is manufactured with outstanding mechanical properties to offer extreme versatility in various designs for separators, as a main component or as additional adhesive separator coatings. In addition, this high-performance, flexible polymer can be modified to create dense gelled or porous separator membranes, as well as traditional solvent-based coatings or industry-first, water-based coatings. Solef® PVDF offers all the benefits of a high-purity resin with chemical and electrochemical stability, fast wettability, controlled leakage of electrolytes and outstanding adhesion even in the harsh environments found in a lithium battery.

 

Solvent-Based Versus Water-Based Separators

Traditional, solvent-based separator coatings in Li-Ion batteries improve the interface between the electrodes and separators to extend cycle life and improve wettability and assembly. Solvay’s unique solvent-based PVDF separator coating is manufactured with Solef® PVDF, a modified copolymer that offers good adhesion, excellent chemical resistance and high lamination strength.

With the introduction of the industry’s first commercialized water-based PVDF for separator coatings, Solvay’s Solef® PVDF Water Based Coatings avoid usage of irritant organic solvents and are available in various grades for formulation flexibility and ease of processing. Solef® XPH, our family of latex PVDF copolymers, utilizes a completely solvent-free coating process and provides OEMs with a high-performing, eco-friendly solution separator coatings.

 

Solef® PVDF for battery separators

Solef-pvdf-grades-for-battery-separators

 

Optimized Processing and Manufacturing

As lithium battery applications continue to evolve, OEMs require binders and separators with more advanced and flexible properties than ever before to facilitate streamlined formulation and manufacturing. Solvay’s specialty polymers for lithium battery binders are designed with medium-high molecular weight to provide excellent adhesion for simplified, easy and safe manufacturing processes and slurry preparation. Our versatile materials for Li-Ion separator membranes and coatings offer a variety of grades and flexibility to satisfy requirements in a range of applications.

 

Cell Gaskets

Advanced Fluoropolymers for Critical Seals

As Li-Ion battery technology evolves, Solvay provides OEMs with high-performance fluoropolymers for cell gaskets to extend battery life and improve battery processing safety. Specifically Hyflon® MFA® (perfluoropolymer) and Tecnoflon® FKM (fluoroelastomer) deliver critical sealing properties with superb chemical, flame and high voltage resistance for improved processability and exemplary sealing performance during operation. Hyflon® MFA® is equipped with exceptional chemical inertness and flame resistance to deliver longevity and durability in modern Li-Ion batteries. Tecnoflon® FKM exhibits excellent mold flow and release to ensure good processability of cell gaskets. These fluorinated materials provide Li-Ion battery manufacturers with cost-effective component design flexibility while meeting the industry’s advanced performance requirements.