Polar interaction of polymer host-solvent enables stable solid electrolyte interphase in composite lithium metal anodes

The lithium(Li) metal anode is an integral component in an emerging high-energy-density rechargeable battery.A composite Li anode with a three-dimensional(3 D) host exhibits unique advantages in suppressing Li dendrites and maintaining dimensional stability.However,the fundamental understanding and regulation of solid electrolyte interphase(SEI),which directly dictates the behavior of Li plating/stripping,are rarely researched in composite Li metal anodes.Herein,the interaction between a polar polymer host and solvent molecules was proposed as an emerging but effective strategy to enable a stable SEI and a uniform Li deposition in a working battery.Fluoroethylene carbonate molecules in electrolytes are enriched in the vicinity of a polar polyacrylonitrile(PAN) host due to a strong dipole-dipole interaction,resulting in a LiF-rich SEI on Li metal to improve the uniformity of Li deposition.A composite Li anode with a PAN host delivers 145 cycles compared with 90 cycles when a non-polar host is employed.Moreover,60 cycles are demonstrated in a 1:0 Ah pouch cell without external pressure.This work provides a fresh guidance for designing practical composite Li anodes by unraveling the vital role of the synergy between a 3 D host and solvent molecules for regulating a robust SEI.

Dispersion of ultrafine alumina in modifier solution ——the role of polar interfacial interaction

Dispersion of ultrafine alumina suspension is examined by using particle size analyzer. The zeta potential and contact angle measurements were used to discuss the electrokinetic behavior and surface wettability of alumina in modifier solution, and to calculate the electrostatic interaction forces and interfacial interaction forces between alumina particles. The aggregation of ultrafine alumina occurs near its PZC. Addition of modifier increases the zeta potential of alumina and its surface hydrophilicity, resulting in increase of electrostatic and hydration repulsion. It makes the suspension of ultrafine alumina completely dispersed. The average particle size of the suspension is decreased from 1.73 μm in absence of modifier to 0.8 μm in the presence of tripolyphosphate. According to polar interfacial interaction approach, the hydration forces responsible for the stability of alumina suspension in the presence of modifier have also been obtained. The extended DLVO theory is successful to describe the dispersion behavior of ultrafine alumina in modifier solution.

Aggregation/dispersion of ultrafine silica in flotagent solution

The aggregation/dispersion of ultrafine particles is of interest for both fundamental and practical perspective. These behaviors of ultrafine silica in flotagent solution and the heter coagulation of silica and alumina were examined using particle size analyzer, electrokinetic potential, contact angle measurements. The flotation reagents have a pronounced effect on the aggregation or dispersion behaviors of ultrafine silica suspensions. Collector dodecylamine chloride renders silica surfaces hydrophobic and the aggregation between silica particles takes place. Modifier tripolyphosphate makes the silica surface completely hydrophilic and enhances the stability of silica suspension. These experimental results can be explained based on the extended DLVO theory by considering polar interfacial interaction between particle surfaces.

Magic wavelengths for 6s_(1/2)→5d_(3/2,5/2)transitions of Yb~+ions

The wave functions,energy levels and matrix elements of Yb+ions are calculated using the relativistic configuration interaction plus core polarization(RCICP)method.The static and dynamic electric dipole polarizabilities of the ground state and low-lying excited states are determined.Then,the magic wavelengths of the magnetic sublevel 6s_(1/2,m=1/2)→5d_(3/2,m=±3/2,±1/2)and 6s_(1/2,m=1/2)→5_(d5/2,m=±5/2,±3/2,±1/2)transitions in the linearly,right-handed,and left-handed polarized light are further determined.The dependence of the magic wavelengths upon the angle between the direction of magnetic field and the direction of laser polarization is analyzed.

High-Order-Harmonic Generation from a Relativistic Circularly Polarized Laser Interacting with Over-Dense Plasma Grating

The simple surface current model is extended to study the generation of high-order harmonics for a relativistic circularly polarized laser pulse interacting with a plasma grating surface. Both exact relativistic electron dynamics and optical interference of surface periodic structure are considered. It is found that high order harmonics in the specular direction are obviously suppressed whereas the harmonics of the grating periodicity are strongly enhanced and folded into small solid angles with respect to the surface direction. The conversion efficiency of certain harmonics is five orders of magnitude higher than that of the planar target cases. It provides an effective approach to generate a coherent radiation within the so-called ＇water window＇ while maintaining high conversion efficiency and narrow angle spread.