A team of researchers has introduced an innovative binder and electrolyte that does not contain fluorine, aimed at promoting environmentally friendly, high-performance battery technology.
A research team, spearheaded by Professor Soojin Park and Seoha Nam from the Department of Chemistry at POSTECH, in collaboration with Hansol Chemical’s Battery Materials R&D center, has created a new fluorine-free binder and electrolyte intended to enhance sustainable, high-performance battery technology. Their work has recently been featured in the Chemical Engineering Journal, a prominent publication in the chemistry field.
As worries about the environment grow, the significance of using sustainable materials in battery technology is becoming increasingly evident. Conventional lithium batteries use fluorinated compounds like polyvinylidene fluoride (PVDF) for binders and lithium hexafluorophosphate (LiPF6, LP) as salts. Unfortunately, this “PVDF-LP” configuration releases poisonous hydrogen fluoride (HF), diminishing battery effectiveness and lifespan. Additionally, PVDF is not biodegradable, and due to stricter regulations on PFAS from the European Union (EU), a ban on such substances is anticipated by 2026.
The research team at POSTECH and Hansol Chemical has crafted a non-fluorinated battery system that adheres to forthcoming environmental regulations while also improving battery performance. They developed an electrolyte based on lithium perchlorate (LiClO4, LC) to substitute the fluorinated LP electrolytes and a non-fluorinated aromatic polyamide (APA) binder utilizing Hansol Chemical’s specialized technology. This groundbreaking “APA-LC” system is completely devoid of fluorinated materials.
The “APA binder” enhances the connection between the active material of the cathode and the aluminum current collector, effectively avoiding electrode degradation in the electrolyte, and greatly prolonging battery longevity. Moreover, the “LC system,” infused with lithium chloride (LiCl) and lithium oxide (Li2O), reduces the energy barrier at the interface, facilitating ion movement and resulting in quicker lithium diffusion and improved output performance when compared to the traditional LP system. Overall, the APA-LC system showed better oxidation stability than the standard PVDF-LP system and maintained a 20% higher capacity retention after 200 cycles at a rapid charge/discharge rate of 1 C, within the voltage range of 2.8-4.3 V in a coin cell evaluation.
The research team successfully applied the APA-LC system to create a high-capacity 1.5 Ah (ampere-hour) pouch cell. This cell exhibited excellent discharge capacity and showcased impressive performance during fast-charging tests. This is the first instance of a battery system that is entirely scalable and feasible, made completely from non-fluorinated components, without any fluorinated materials.
Professor Soojin Park from POSTECH articulated the significance of the research, stating, “We’ve not only replaced fluorinated systems; we’ve demonstrated high-capacity retention along with remarkable stability.” He further commented, “Our approach will propel the sustainability of the battery industry, helping to facilitate a transition towards non-fluorinated battery systems while meeting environmental standards.”
Young-Ho Yoon, Managing Director of Hansol Chemical’s Secondary Battery Materials Business, noted, “By tackling concerns surrounding PFAS regulations, we’ve established a foothold in the global cathode binder market, which is anticipated to reach KRW 1.7 trillion by 2026.” He further remarked, “Ongoing research will strengthen our status as a top supplier of environmentally friendly secondary battery materials.”
