Sulfolane for Emerging Batteries

Sulfolane Advantages in Breakthrough Battery Technologies

---

Many newer battery technologies show immense promise as the next frontier in energy storage. For example, solid-state batteries (SSBs) offer several potential advantages over conventional lithium-ion batteries, including improved safety, increased energy density, and longer lifespan. However, one of the primary challenges in battery development is finding suitable electrolytes that can conduct ions effectively while maintaining battery stability. Sulfolane, a sulfone solvent known for its excellent thermal and chemical stability, shows promise as a possible electrolyte candidate.

Sulfolane has unique properties that make it an attractive electrolyte option in solid-state batteries. The high dielectric constant, low volatility, and electrochemical stability of sulfolane make the solvent well suited for use in many electrolytes, where stability and conductivity are critical requirements. Sulfolane also demonstrates the ability to dissolve a variety of electrolyte salts, permitting the customization of electrolyte formulations for specific battery chemistries.

Sulfolane, when used in concentration with other electrolyte materials, such as saltlike lithium bis(fluorosulfonyl)imide (LiFSI), has shown exceptional anodic stability and long-term cycling stability in liquid lithium-ion electrolytes and gelled for solid-state lithium-graphite batteries. Sulfolane-based LiFSI electrolyte solutions have shown superior oxidation stability, have a high dielectric constant, and are nonflammable—three critical characteristics needed in a high-performing electrolyte. In some studies, LiFSI sulfolane electrolytes have a high Coulombic efficiency, meaning the battery loses less capacity in each charge and discharge cycle, potentially extending its lifespan. They have also demonstrated long-term, stable lithium plating and stripping cycling.

Additionally, sulfolane’s compatibility with a wide variety of solid electrolyte materials gives it a key advantage in solid-state batteries. Unlike traditional liquid electrolytes that react with solid electrolyte interfaces (SEIs) and degrade battery performance over time, sulfolane-based electrolytes promote stable and uniform SEIs, thereby improving energy density and overall battery performance.

Furthermore, sulfolane demonstrates exceptional ion conductivity, facilitating the transport of lithium ions within the battery cell and contributing to faster charge and discharge rates. Faster charging makes SSBs a more suitable technology for high-power applications like electric vehicles and grid storage. The high ion conductivity of sulfolane-based electrolytes also reduces the formation of dendrites, problematic growths that can short-circuit batteries and cause safety hazards.

Sulfolane also has very high thermal stability. Unlike traditional liquid electrolytes that vaporize and deteriorate at high temperatures, sulfolane-based electrolytes can withstand elevated temperatures without compromising battery performance or safety. The thermal stability of sulfolane expands the operating temperature, making it a suitable solution for batteries exposed to harsh and outdoor environments.

Lastly, the low viscosity offers practical advantages to battery manufacturing and performance. The low viscosity of the solvent facilitates the impregnation of electrolytes into porous solid electrolyte scaffolds, allowing for the development of flexible and thin battery designs. This opens up new possibilities for SSBs, from wearable devices to large-scale energy storage systems.  Viscosity can also impact the wettability of the separator, affect penetration into the electrode pores, and play a role in ionic conductivity.

CP Chem Sulfolane Portfolio 

---

Chevron Phillips Chemical is a global leader in the manufacture of various high-purity solvents, including high-purity sulfolane. They have been producing sulfolane for over 50 years and have extensive knowledge and experience in using and handling sulfolane, including potential recycling opportunities that further improve its sustainability footprint. Chevron Phillips Chemical is committed to the quality and sustainability of their products and is partnered with ChemPoint to deliver localized warehousing and reduced lead times to our customers. Below are the sulfolane products from Chevron Phillips Chemical suitable for battery applications.

 

Chevron Phillips Chemical has developed a low-water version called Sulfolane Dry that is not yet commercialized. Sulfolane Dry has a higher purity and lower metals and water content. Low water content is critical in battery applications as water will be electrolyzed into H2 and O2, creating buildup that could lead to premature failure. Contact us today to speak with a technical representative and request a sample.