Room-temperature solid-state sodium batteries (SSBs) are viewed as one of the most promising candidates for next-generation energy storage devices because of their cost-effectiveness, safety performance, and high energy density. Na + ion superionic conductor (NASICON) type solid electrolyte (SE) shows great perspective due to its high ionic conductivity at room temperature. However, the high interfacial resistance between Na metal anode and NASICON SE is still thwarting the stable operation of SSBs. In this work, we successfully reduce the Na|NASICON interfacial resistance from 1658 to 101 Ω•cm 2 by lowering surface tension of Na metal via compositing Na metal with amorphous SiO 2 . Enabled by the enhanced interface contact, the solidstate Na-SiO 2 |NASICON|Na-SiO 2 symmetric cell can endure current density up to 500 μA/cm 2 and stably cycle for more than 135 h, while Na|NASICON|Na symmetric cell shorts in less than 10 h under 100 μA/cm 2 . This Letter provides an effective route to form close contact between Na metal anode and NASICON SE and fuels studies concerning Na|NASICON interface in the future.

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In this work, the boron nitride (BN) nanosheets were dispersed in natural esters to fabricate the dielectric nanofluid. Microstructures and chemical compositions of the nanosized BN are determined. The stability, viscosity, and thermal conductivity of the BN nanofluid, were obtained. And the dissipation factor, electrical conductivity, and relative permittivity of the BN nanofluid, were measured. The ion mobilities and migrating times of the nanofluid were measured under different volumetric fractions of BN nanosheets and temperatures. Results show that the electrical conductivity and dissipation factor of the nanofluid decreased by 54% and 48% with the addition of only 0.1% of BN nanosheets under 110°C. Both the half‐reduced carrier mobility of the nanofluid and the declined ion concentration by blocking of BN nanosheet contributed to the exponentially reduced electrical conductivity and enhanced dielectric performances of the BN nanofluid. The suppression coefficient k is proposed to quantitatively describe the hinder effect of ion migration in nanofluids by 2D BN nanosheet. Results provide a strategy to design and develop advanced nanofluids with low‐dielectric loss by aids of surface adsorption of ion and steric hindrance of 2D nanosheets.

In this research, the magnetic UiO-66-NH 2 composites were prepared and applied as adsorbents for the effective removal of salicylic acid (SA) and acetylsalicylic acid (ASA) from aqueous media. The as-prepared adsorbent inherits both the excellent properties of metal organic frameworks and the magnetic separation property of magnetic material, which makes the magnetic UiO-66-NH 2 composite exhibit a rapid separation rate and high capacity. The adsorption kinetics were well fitted with the pseudo-second-order model, and the adsorption isotherm could be well explained using the Langmuir isotherm. The dominant mechanism for adsorption of SA and ASA was hydrogen-bonding, the affinity of carboxyl groups with Zr−O clusters, and electrostatic interactions. The high adsorption capacities, easy separation process, fast adsorption kinetics, and satisfactory reusability of the magnetic UiO-66-NH 2 give it fantastic potential as adsorbents for adsorptive separation of pharmaceutical contaminants from aqueous media.

Natural esters, as the renewable resources, offer excellent physiochemical and dielectric properties such as the fire-resistance, high biodegradability and satisfactory dielectric breakdown performance. Thus, natural esters are selected as the insulation and heat dissipation medium for electrical equipment. However, the electrical performance of natural esters with different structures under the long gap and higher electrical stress needs further evaluations. In this paper, streamer propagation of various natural esters under the long gap and higher electrical stress were observed optically. The influence of voltage polarity, liquid types and gap distances on streamer characteristics of natural esters were analyzed. Results show that the maximum propagation velocity of streamer in natural esters is greater than that in the hydrocarbon liquids. Breakdown voltage of natural esters under negative polarity is much higher than that under positive polarity for the same gap distance. Among all the natural esters concerned, the camellia liquid demonstrates slower streamer velocity and slight greater lightning breakdown voltages for the positive and negative polarity. The lower content of unsaturation triacylglycerol molecules in camellia liquid contributes to the inhibition of ionization and streamers propagation. Results would be valuable reference for the design, manufacture and operation of the electrical equipment filled with natural ester.