Liquid electrolytes lithium hexafluorophosphate

A gel electrolyte consists of an ion conducting polymer, such as polyoxyethylene or a polymer with polyoxyethylene segment, and an ion source. Hexafluorophosphate or tetrafluoroborate salts of lithium are commonly employed as the ion source. Other common components of the gel are liquid electrolytes like ethylene carbonate or propylene carbonate, both of which are used to increase the overall ion conductivity. Cross-linking agents, such as photo cross-linked acrylates or polyurethanes, can be incorporated to improve the mechanical stability of gel electrolytes. 

Most liquid electrolytes used in commercial lithium-ion cells are nonaqueous solutions, in which roughly 1 mol dm of lithium hexafluorophosphate (LiPF ) salt is dissolved in a mixture of carbonate solvents selected from cyclic carbonates, e.g., ethylene carbonate (EC) and propylene carbonate (PC), and linear carbonates, e.g., dimethyl carbonate (DMC), ethyl methyl carbonate (EMC), and diethyl carbonate (DEC), as listed in Table 2.1 [1]. 

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