The fluorine-free battery system is characterized by high capacity and stability

Reviewed by Lexie CornerSeptember 27, 2024

An international group of researchers from POSTECH, in collaboration with Hansol Chemical’s Battery Materials Research and Development Center, has developed a new fluorine-free electrolyte and binder to advance high-performance and environmentally friendly battery technology. The results were published in the journal ” Journal of Chemical Engineering.

As environmental concerns increase, materials are becoming increasingly important in battery technology. Traditional lithium batteries use fluorinated substances such as lithium hexafluorophosphate (LiPF₆LP) and polyvinylidene fluoride (PVDF) binders. However, these materials release toxic hydrogen fluoride (HF), which impairs battery performance and life. Additionally, PVDF is not biodegradable and the European Union (EU) is expected to ban these compounds by 2026 due to stricter PFAS regulations.

To address these issues, researchers from POSTECH and Hansol Chemical have developed a non-fluorinated battery system that increases performance while ensuring compliance with upcoming environmental regulations. Using Hansol Chemical’s patented technology, they created lithium perchlorate (LiClO₄LC-based electrolyte) to replace fluorinated LP electrolytes and combined it with a non-fluorinated aromatic polyamide (APA) binder. The resulting “APA-LC” system is completely free of fluorinated substances.

The “APA binder” significantly extends battery life by strengthening the bond between the active cathode material and the aluminum current collector, thereby preventing corrosion of the electrode in the electrolyte. Additionally, the “LC system” reinforced with lithium oxide (Li₂O) and lithium chloride (LiCl), reduce the energy barrier at the interface, facilitating ion migration, accelerating lithium diffusion, and improving output efficiency compared to the current LP system.

In the coin cell battery test, the APA-LC system demonstrated 20% higher capacity retention after 200 cycles at a high charge/discharge rate of 1 C, over a voltage range of 2.8-4.3 V, demonstrating improved oxidation stability compared to the traditional system PVDF-LC. lp system

Using APA-LC technology, the research team developed a high-capacity 1.5 Ah pocket battery that maintained high performance and excellent discharge capacity during fast charging tests. This is the first successful demonstration of a fully scalable and practical battery system that is completely free of fluorine compounds.

We didn’t just replace fluorinated systems; We have proven to maintain high capacity and exceptional stability. Our solution will increase the sustainability of the battery industry by facilitating the transition to non-fluorinated battery systems while ensuring compliance with environmental requirements.

Soojin Park, professor at Pohang University of Science and Technology

Young-Ho Yoon, managing director of Hansol Chemical’s secondary battery materials division, said: “By addressing PFAS regulatory issues, we have secured a foothold in the global cathode binder market, which is estimated to reach KRW 1.7 trillion by 2026. Further research will strengthen our position as a leading supplier of environmentally friendly secondary battery materials“

Magazine number:

Nam, S., et al. (2024) All high-performance fluorine-free lithium-ion batteries. Journal of Chemical Engineering. doi.org/10.1016/j.cej.2024.154790.