Herein, a series of lithium greases, with different thickener concentrations, fibers morphologies, and
types of base oil, was synthesized via the saponification reaction. The corresponding rheological
behaviors, such as structural strength, structural rearrangement speed, and recoverability, were
investigated carefully. Results indicate that greases with higher entanglement levels of thickener fibers
display higher structure strength, lower structural rearrangement speed, and lower recoverability. On the
other hand, greases with a lower level of entanglement show counter trends. In addition, the structure
strength dramatically decreases with a decrease in thickener concentration; this is accompanied by a
significant increase in structural rearrangement speed and recoverability. Furthermore, the difference in
these rheological behaviors between greases becomes narrow with a decrease in the fiber entanglement
level. In addition, the influence of functional groups of base oil on the rheological behaviors was
investigated. By introducing base oils with rigid molecular chains (containing ester bond and aromatic
ring), the structure strength of lithium greases improved remarkably, especially for greases with a lower
entanglement level. Moreover, the results of tribological tests indicate that the lithium greases with a fast
structural rearrangement speed display better friction-reducing property in the frequency ramp tests. On
the other hand, greases with a higher structure strength display good load-bearing property.