Fluorine-free organic batteries with solid polymer electrolytes
Guiomar Hernández
Uppsala University
Organic batteries are more sustainable and cost-effective than lithium-ion batteries that contain transition metals. However, the short lifetime of organic batteries is still hindering their full potential, mainly from the dissolution of the active material in typical liquid electrolytes. In order to mitigate this issue, redox-active molecules are incorporated into a polymer structure and solid polymer electrolytes are used instead of the conventional liquid systems. To further improve sustainability, fluorinated binders and salt anions should be replaced with fluorine-free alternatives.
This work investigates the performance of a p-type redox-active polymer, poly(3-vinyl-N-methyl-phenothiazine), combined with solid polymer electrolytes based on poly(ethylene oxide) and poly(ɛ-caprolactone). The effect of the salt anion on the redox reaction has also been studied with hexafluorophosphate, bis(trifluoromethanesulfonyl)imide (TFSI) and bis(oxalato)borate (BOB).