Tribological Properties of Alkylphenyl Diphosphates as High-Performance Antiwear Additive in Lithium Complex Grease and Polyurea Grease for Steel/Steel Contacts at Elevated Temperature

The alkylphenyl diphosphates pentaerythritol tetrakis­(diphenyl phosphate) (PDP) and trimethylolpropane tris­(diphenyl phosphate) (TDP) were evaluated as the antiwear additives in lithium complex grease and polyurea grease at 200 °C. The results indicated that both additives may effectively reduce the sliding friction and wear as compared to the base greases. The tribological performances were generally better than the normally used molybdenum disulfide (MoS₂)-based additive package in lithium complex grease and also in polyurea grease. Boundary lubrication films composed of Fe­(OH)­O, Fe₃O₄, FePO₄, and compounds containing the P–O bonds were formed on the worn surface, which resulted in excellent friction reduction and antiwear performance

Fluoride-Based Artificial Interface for a Highly Reversible Zn Metal Anode Interlayer in Aqueous Zinc-Ion Batteries

Zn metal is considered as one of the best anode alternatives for rechargeable aqueous zinc-ion batteries (AZIBs) due to its high theoretical capacity (820 mAh g–1 and 5855 mAh cm–3), low electrochemical potential (−0.76 V vs standard hydrogen electrode), abundance, and safety. However, some irreversible problems such as dendrite growth and parasitic side reactions are knotty issues that seriously affect the cycle stability and Coulombic efficiency. Here, we rationalize the design of a modified interlayer of MgF2 nanocrystals grown on a monolayer MoS2 substrate (MDMF) on the surface of Zn. The introduced fluorine atom plays a significant role in motivating fast Zn2+ transfer kinetics as a zincophilic site, which can be partially converted to ZnF2 as an artificial solid Zn2+ conductor to further guide uniform zinc deposition. This inorganic layer successfully could induce dendrite-free Zn deposition at the interface, inhibiting Zn dendrite formation and interfacial side reactions. As a result, the MDMF@Zn anode achieved high reversibility with 99% Coulombic efficiency and long cycle stability of 700 cycles at 5 mA cm–2, demonstrating ultrastable stripping/plating behavior. In addition, the assembled MDMF@Zn//V2O5 full cell showed good cycling stability (150.9 mAh g–1 after 1000 cycles at a current density of 1.0 A g–1) and excellent rate performance. Accordingly, the intermediate layer described in this work provides a new insight into designing stable and dendrite-free AZIBs