Tribological Properties and Electrical Conductivity of Lithium Salts in Lubricant Oil

The influence of lithium tetrafluoroborate (LiBF₄),lithium bis(trifluoromethanesulfonyl) imide (LiNTf₂) and lithium hexafluorophosphate (LiPF₆) as additives on tribological properties of base oil is investigated using an MFT-R4000 reciprocating friction and wear tester. The wear volumes were determined by an OLS4000 3D topography measurement profiler. The morphologies of worn surfaces of the discs were examined using a scanning electron microscope. The salinity and conductivity of the oil were measured using a DDSJ-308A conductivity meter. And the relationship between the lithium salts concentration and conductivity was elucidated. The results show that the lithium salts reduced the friction coefficient and enhanced the anti-wear property. The lithium salts greatly improved the conductivity of the base oil.