Sodium hexafluorophosphate is primarily used as an electrolyte salt in lithium-ion batteries. It enhances the conductivity and stability of the electrolyte, improving battery performance and lifespan. Additionally, it is employed in electrochemical applications, such as supercapacitors and fuel cells, due to its high ionic conductivity and thermal stability. In organic synthesis, it serves as a counterion in phase-transfer catalysis, facilitating reactions in non-polar solvents. Its use in chemical research includes acting as a reagent for studying ion transport mechanisms.