All fluorine-free lithium-ion batteries with high-rate capability
Seoha Nam, Hoonmoh Seong, Yeongseok Kim, Kwangin Kim, Changbeom Kim, Seman Kwon, Soojin Park
Abstract
Fluorinated compounds, including per- and polyfluoroalkyl substances (PFAS), are crucial in battery technologies for their exceptional thermal and chemical resistance but pose significant environmental and health risks. Facing potential bans by the European Chemicals Agency post-2026, this study introduces non-fluorinated alternatives to meet the needs of high-energy–density lithium batteries in a completely fluorine-free environment. We have replaced traditional fluorinated lithium hexafluorophosphate-based electrolytes and poly(vinylidene fluoride) binders with an optimized lithium perchlorate-based electrolyte offering extended oxidation stability up to 5 V and a newly synthesized aromatic polyamide binder with remarkable binding strength derived from its polar groups (–CONH-, −O=S=O-, and –COOH). This shift demonstrates robust oxidation resistance without fluorine, improving the performance of fluorine-free graphite/NCM811 lithium-ion batteries, which exhibit superior fast-discharging capabilities and cycling stability under 2.8–4.3 V at 1 C, outperforming traditional fluorinated cells. Furthermore, the successful development of an all-fluorine-free 1.5 Ah pouch cell confirms the viability of non-fluorinated materials for high-capacity battery applications.