Recently, the application of LiFePO₄ (LFP) batteries in electric vehicles has attracted extensive attention from researchers. This work presents a composite of LFP particles trapped in reduced graphene oxide (rGO) nanosheets obtained through the high-temperature reduction strategy. The obtained LiFePO₄/rGO composites indicate spherical morphology and uniform particles. As to the structure mode of the composite, LFP distributes in the interlayer structure of rGO, and the rGO evenly covers the surface of the particles. The LFP/rGO cathodes demonstrate a reversible specific capacity of 165 mA h g⁻¹ and high coulombic efficiency at 0.2 C, excellent rate capacity (up to 10 C), outstanding long-term cycling stability (98%) after 1000 cycles at 5 C. The combined high electron conductivity of the layered rGO coating and uniform LFP particles contribute to the remarkable electrochemical performance of the LFP/rGO composite. The unique LFP/rGO cathode provides a potential application in high-power lithium-ion batteries.

Imidazolium and pyridinium-based ionic liquids (ILs) have attracted increasing attention in the extraction of aromatic VOCs. However, fundamental studies on the mechanism of capturing aromatic VOCs have been less reported. In this work, the interactions between two ILs, 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide (EMIMTFSI) and N-butylpyridinium bis(trifluoromethylsulfonyl)imide (BpyTFSI), and toluene (C₆H₅CH₃), were investigated by using attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR), excess infrared spectroscopy, hydrogen nuclear magnetic resonance (¹H NMR) spectroscopy and quantum chemical calculations. Some conclusions were obtained as follows: (1) H atoms on EMIMTFSI/BpyTFSI were located above or below the benzene ring and were mainly formed as C2–H⋯π bonds and C2,6–H⋯π bonds with C₆H₅CH₃, respectively. C–H⋯π bonds played a significant role in capturing aromatic compounds. (2) Upon adding C₆H₅CH₃, the two IL-C₆H₅CH₃ system's interaction strength was as follows: EMIMTFSI-C₆H₅CH₃ > BpyTFSI-C₆H₅CH₃. (3) Since C₆H₅CH₃ was unable to disrupt the interactions between cations and anions of ion pairs in the two studied IL-C₆H₅CH₃ systems, only ion cluster-C₆H₅CH₃ and ion pair-C₆H₅CH₃ complexes were observed. This work may provide theoretical insights into the separation mechanism for capturing VOCs.

There have been some studies on the microscopic properties of ester-functionalized ionic liquids (ILs), but the microscopic properties of their mixtures with co-solvents have seldom been reported. In practical applications, ILs are usually used together with co-solvents. Therefore, it is very important to study the microstructure of ester-functionalized ILs and co-solvents. In this work, the hydrogen bonding interactions between ester-functionalized IL 1-acetoxyethyl-3-methylimidazolium tetrafluoroborate (AOEMIMBF₄) and DMSO were studied using spectroscopic methods and quantum chemical calculations. Non-functionalized IL 1-butyl-3-methylimidazolium tetrafluoroborate (BMIMBF₄) and DMSO were used for comparison. The results indicate that (1) by adding DMSO, the hydrogen bonding interactions of ν(C2–H) were enhanced, and DMSO could form hydrogen bonds with anions and cations simultaneously. (2) The incorporation of an ester group could enhance the hydrogen bonding interactions. (3) Both the stretching vibration of C2–H and CO indicated changes in the microscopic structure: AOEMIMBF₄ ion clusters first interacted with DMSO, then broke into AOEMIMBF₄–DMSO complexes and finally existed as [AOEMIM]⁺/[BF₄]⁻–DMSO complexes.

A novel giant magnetoimpedance (GMI) noncontact current sensor with spiral structure double-probe is designed. Differing from the formerly reported sensors, the probes of this sensor consist of annealed commercial amorphous ribbons which are curled to spiral tubes. Two couples of permanent magnets are applied to provide bias magnetic field. The distance between the probes and the permanent magnets is fixed at 2.4 cm. The sensor shows sensitivity of 1 V/A in the current range of plusmn1.5 A, measurement precision of less than 0.16% at room temperature, and good thermal stability in the temperature range between -20 and 30degC.