Borophene as Conductive Additive to Boost the Performance of MoS₂‑Based Anode Materials

Carbon-based materials, including graphene, porous carbon, and nanotubes, have been widely used as conductive additives to reduce the resistance in semiconductive anode materials of lithium-ion batteries (LIBs) toward better performance and the alleviated battery overheat problem. However, these additives are usually denounced for their low lithium-ion capacity. Moreover, emergence of vacant defect and heteroatom incorporation would open a sizable energy gap accompanied by reduced conductance. Here, by selecting MoS₂ as a prototype system, we proclaim the utilization of emerging borophene as the conductive additive in terms of its low ion-transport barrier and robust metallic conductivity against defects and external doping in addition to its high Li-storage capacity. We found that substantial electrons transfer from MoS₂ to borophene, producing strong electronic coupling that conduces to favorable interface bonding in combination with improved Li affinity. Incorporation of borophene also compensates the poor mechanical property of MoS₂ with increased elastic modulus, ensuring the electrode integrity against pulverization. Furthermore, B/MoS₂ can achieve a maximum Li-storage capacity of 539 mAh/g along with low ion-hopping barriers inherited from its counterparts. Our work brings new opportunities to boost the electrochemical performance of semiconductive anode materials with borophene for LIBs

Experimental Studies of the Separation of C2 Compounds from CH₄ + C₂H₄ + C₂H₆ + N₂ Gas Mixtures by an Absorption–Hydration Hybrid Method

An absorption–hydration hybrid method was employed for separating C2 components (C₂H₄ + C₂H₆) from low-boiling gas mixtures such as refinery dry gas using water-in-diesel emulsions under hydrate formation conditions. Span 20 was used to disperse the water or hydrate in diesel to form the emulsion or hydrate slurry. To simulate a three-stage separation process, three (CH₄ + C₂H₄ + C₂H₆ + N₂) feed gas mixture samples with different gas molar compositions were prepared. Separation experiments were performed under different conditions to investigate the influences of feed composition, temperature, pressure, initial water cut in the emulsion, and initial gas/liquid volume ratio on separation efficiency. The experimental results show that the absorption–hydration hybrid method is obviously superior to the single-absorption method. After three stages of separation at appropriate operating conditions, we found that C2 compounds can be enriched from ∼15 to more than 50 mol % in the (hydrate + diesel) slurry phase and that the content of C2 compounds in the residual gas phase can be reduced to lower than 2 mol %. Low temperature, low initial gas/liquid volume ratio, high pressure, and high water cut were found to be favorable for the recovery of C2 compounds. However, when the temperature was lower than 270.2 K and the water cut was higher than 30 vol %, the formation of flowable hydrate slurry became difficult