Tetrafluoroethylene telomers as electrolyte additives for high-performance, radiation-tolerant lithium and potassium batteries

Abstract

Fluorinated electrolyte additives are extensively utilized to improve the cycling stability and safety of rechargeable batteries, yet their high cost and environmental impact remain a critical concern. Herein, we report the application of tetrafluoroethylene telomers (TFE-T) as a cheap and readily available fluorinated additive to battery electrolytes. When incorporated at low concentrations (2–3 wt% in electrolyte), this additive enhances the electrochemical performance of both lithium-ion and potassium-ion batteries with an array of different inorganic and organic cathodes, including high-voltage nickel-based oxides and organic polyimides. In particular, the presence of the TFE-T additive maintains the structural integrity of NCA cathodes, suppresses Ni²⁺/Li⁺ ion intermixing and enables remarkable radiation resilience of the batteries. The proposed strategy offers a scalable and environmentally conscious approach to developing high-performance battery systems while mitigating the ecological risks associated with conventional fluorinated additives.