An example of a gel electrolyte precursor includes a lithium salt, a solvent, a fluorinated monomer, a fluorinated crosslinker, and an initiator. Another example of a gel electrolyte precursor includes a lithium salt, a solvent, and a fluorinated monomer, wherein the fluorinated monomer is methyl 2-(trifluoromethyl) acrylate, tert-butyl 2-(trifluoromethyl)acrylate, or a combination thereof. A gel electrolyte formed from either gel electrolyte precursor may be incorporated into a lithium-based battery.