No abstract

Highly reactive copper‐dihydride clusters, [Cu15(H)2(S2CNR2)6(C2Ph)6](PF6) {R = nBu (1H), nPr (2H), iBu (3H)}, are isolated during the reaction of [Cu28H15{S2CNnBu2}12](PF6) with ten equivalents of phenylacetylene. They are found to be intermediates in the formation of the earlier reported two‐electron superatom [Cu13(S2CNR2)6(C2Ph)4]+. Better yields are obtained by reacting dithiocarbamate sodium salts, [Cu(CH3CN)4](PF6), BH4− and phenylacetylene. The presence of two hydrides in the isolated clusters is confirmed by the synthesis and characterization of its deuteride analogue [Cu15(D)2(S2CNR2)6(C2Ph)6]+, and a single‐crystal neutron structure of 2H. Structural characterization of 1H reveals a new bicapped icosahedral copper(I) cage encapsulating a linear copper dihydride (CuH2)− unit. Reaction of 3H with Au(I) salts yields a highly luminescent [AuCu12(S2CNiBu2)6(C2Ph)4]+ cluster.

Solid-state rechargeable batteries using polymer electrolytes have been considered, which can avoid safety issues and enhance energy density. However, commercial application of the polymer electrolyte solid-state battery is still significantly limited by the low room-temperature ionic conductivity, poor mechanical properties, and weak interfacial compatibility between the electrolyte and electrode, especially for the room-temperature solid-state rechargeable battery. In this work, a poly­(vinylene carbonate)-based composite polymer electrolyte (PVC-CPE) is reported for the first time to realize room-temperature solid-state sodium batteries with high performances. This in situ solidified PVC-CPE possesses superior ionic conductivity (0.12 mS cm–1 at 25 °C), high Na+ transference number (t Na+ = 0.60), as well as enhanced electrode/electrolyte interfacial stability. Notably, the composite cathode NaNi1/3Fe1/3Mn1/3O2 (c-NFM) is designed through the in situ growth of the polymer electrolyte inside the electrode to decrease interfacial resistance and facilitate effective ion transport in electrode/electrolyte interfaces. It is demonstrated that the solid-state c-NFM/PVC-CPE/Na battery assembled by a one-step in situ solidification method exhibits remarkably enhanced cell performances at room temperature compared with a reference NFM/PVC-CPE/Na assembled through a conventional ex situ method. The battery presents a high initial specific capacity of 104.2 mA h g–1 at 0.2 C with a capacity retention of 86.8% over 250 cycles and ∼80.2 mA h g–1 at 1 C. This study suggests that PVC-CPE is a very promising electrolyte for solid-state sodium batteries. This study also suggests a new method to design high-performance polymer electrolytes for other solid-state rechargeable batteries to realize high safety and considerable electrochemical performance at room temperature.

Polymer modifiers have been used to improve the performances of asphalt binders in pavement engineering. The modifying effect of polymers on asphalt is largely dependent on the morphological characteristics of polymer-modified asphalt. The morphologies of polymer-modified asphalt are composed of a polymer-rich phase, a asphaltene-rich phase, and the interphase between the two phases. Interfacial interactions importantly contribute to the morphology but are commonly overlooked. In this study, carbon nanotubes (CNTs) were selected to improve the interfacial interactions of polymer-modified asphalt. Fluorescence microscopy (FM), scanning electron microscopy (SEM), micro-Raman spectroscopy (MRS), and molecular dynamics (MD) simulation were used to capture the characteristics of the interphase and polymer-rich phase. CNTs-polymer-modified asphalt involves stronger intermolecular forces than those in asphalt-modified by only styrene–butadiene–styrene (SBS) or CNTs. This discrepancy highlights the intensified interfacial interaction in the former material. Raman peak and MD findings reveal that the CC of CNTs interacted with the alkanes and aromatic hydrocarbons of asphalt. SBS were entwined or surrounded with CNTs through the π–π conjugation of the benzene rings of the two components. Consequently, a synergistic effect enhanced the intermolecular force between SBS and CNTs in the interphase. SEM results indicated that CNTs were enriched in the interphase, enhancing mechanical anchorage between the polymer and asphalt. As a result, CNTs increased the roughness of the interphase and produced a prominent cage construction of polymer-rich phase. Moreover, the observed pullout behaviors of CNTs alleviated interfacial failure. FM images displayed that CNTs enhanced the swelling degree of the polymer-rich phase. This effect was realized because CNTs served as a tunnel for transporting saturates, aromatics, and small resin molecules, as shown by molecular dynamics MD analysis. This work revealed the importance of the interfacial interactions on the micromorphologies of polymer-modified asphalt.