Lithium salts are by far the most common type of thickener in lubricating greases. The battery industry is placing increasing demands on lithium supply and pricing, however, and a probable toxin classification of precursor material looms. It is thus important to explore a transition to a lithium-independent lubricant industry. In addition to providing the consistency properties of grease, a primary function of the thickener is to act as a passive lubricant supply system, releasing oil into the contact and making functional additives available to the surface as required. In this study, the performance of lithium complex grease was stress-tested by subjecting it to highly loaded rolling-sliding contact conditions that are now commonplace in modern machines. Tribological evaluation and Time-of-Flight Secondary Ion Mass Spectrometry analysis of tribofilms together reveal serious limitations in the properties of lithium thickeners; instead, a lithium-free grease matrix system, based on polypropylene, is shown to display better lubricating performance, rendering it a viable and more effective alternative.