A novel instrument allows for the first time measurements of the lateral adhesion forces at a solid-liquid interface, f(parallel), in a way that is decoupled from the normal forces, f(perpendicular). We use it to measure how f(parallel) between a drop and a surface is influenced by different f(perpendicular) and different histories of drop resting periods on the surface prior to sliding, t(rest). The variation of f(parallel) with t(rest) is similar for different f(perpendicular) and always plateaus as t(rest)-->infinity. We show that the f(parallel) plateau value is higher when f(perpendicular) is lower. This seemingly counterintuitive result is in agreement with recent theories.

In lithium-ion batteries, chemical additives are used as co-solvents to primary electrolytes to improve capacity and power retention. These additives facilitate the formation of a passivation layer, the solid electrolyte interphase (SEI), on the electrode surface. In this work, SEIs are formed in neat electrolyte and in electrolyte containing fluoroethylene carbonate and vinylene carbonate. The formed SEIs are then compared using a redox couple to probe their physical properties. For passivated samples, the impedance response of the redox couple shows the presence of multiple time constants, with processes at longer time scales corresponding to redox couple transport in the porous layer of the SEI. Samples passivated with additive-containing electrolyte versus neat electrolyte exhibit less redox-couple kinetic and mass-transport impedance. Simulations of the electrode-electrolyte interface indicate that compact and porous layer growth lead to slowed redox kinetics and mass transport. Model results suggest that SEI thicknesses are found to be at least an order of magnitude larger than expected compared to graphite electrodes. SEM cross sections of SEIs formed by neat and additive-containing electrolyte support the model findings. Experimentally measured formation charges, coupled with FTIR measurements of SEI composition, suggest that polymerization reactions are causing the unexpected film growth. In lithium-ion batteries, formation and growth of the solid electrolyte interphase (SEI) is a well-established mode of capacity and power fade. 1,2 Cell characteristics, including electrode chemistry and primary electrolyte composition, influence the chemical and physical properties of SEIs formed. 3 In addition to the primary electrolyte, chemical additives have been incorporated as co-solvents to address SEI formation and growth. When included as co-solvents, both fluoroethylene carbonate (FEC) and vinylene carbonate (VC) electrolyte additives preferentially react with the electrode during the SEI formation process instead of the primary electrolyte. Improved capacity retention, calendar life, and thermal stability are observed with additive inclusion in the electrolyte mixture. Additives such as FEC and VC have been prescribed as co-solvents to primary electrolytes for a variety of electrode chemistries. [4][5][6][7][8] Several groups have investigated the efficacy of these co-solvents to enhance cell performance. In these studies, the additives are limited to less than or equal to ten weight percent of the total electrolyte. For example, Ryou et al. found improved capacity retention at 60 • C with the addition of FEC, for a graphite negative electrode and LiMn 2 O 4 positive electrode full cell. 7 Bordes et al. found that, for a silicon-graphene composite negative electrode, FEC enhanced electrochemical performance by forming a less resistive SEI with smaller thickness using impedance spectroscopy and electron microscopy. 9 Aurbach et al. observed improved capacity with the addition of VC to a graphite negative ele...

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Solid concentration changes may affect the solid-liquid flow of the axial flow pump in the polypropylene loop reactor, accompanied with unstable operations (e.g., axial power fluctuation). The influencing factors and formation mechanisms of axial power fluctuation were analysed. After that, to discuss the influences of energy allowance of the mixture media in the loop reactor, the internal flow status of the pump under different solid volume fractions were compared. Then a head-correction strategy of operating control with single invert was proposed, to smooth the axial power fluctuation of the axial flow pump. Results demonstrate that viscosity of the mixture media is positively related, whereas the head of the axial flow pump is negatively correlated with solid concentration. Besides, head-correction curves can effectively regulate the off-design operation of pump under different solid volume fractions, with the energy allowance and the axial power fluctuation reduced in the loop reactor and the pump. Researches provide important references for the analysis of internal flow status and the solution of axial power fluctuation of the axial flow pump in the polypropylene loop reactor.

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