Dehydrofluorination behavior of poly(vinylidene fluoride) during thermal treatment using calcium carbonate

Various fluorine compounds types, such as electrolytes and binders, are present in lithium-ion batteries (LIBs). The novel pyrometallurgical process is applicable for metal recovery from spent LIBs; however, it results in the emission of toxic fluorides such as hydrogen fluoride (HF). For the safe treatment of spent LIBs, we investigated HF emission behavior during thermal treatment of poly(vinylidene difluoride) (PVDF) as the binder model. To suppress the emission of HF, we also examined the effect of calcium carbonate (CaCO3) addition. It was found that HF emission was suppressed from 72% of total F for pure PVDF to 0.8% through CaCO3 addition. Fluorine was fixed as stable calcium fluoride.

Automated summary

Various fluorine compounds, such as electrolytes and binders, are present in lithium-ion batteries. A novel pyrometallurgical process for metal recovery from spent LIBs emits toxic fluorides like hydrogen fluoride. Investigating HF emission behavior during thermal treatment of PVDF as the binder model, it was found that addition of calcium carbonate effectively suppressed the emission of HF.