Constructing Bidirectional Fluorine-Rich Electrode/Electrolyte Interphase Via Solvent Redistribution toward Long-Term Sodium Battery

The high concentration electrolytes with specific solvation structure could passivate the electrodes to prolong battery cycle life but at the expense of increased cost,which limits the wide application in commercialization.The regular concentration(1_(M))electrolytes with suitable properties(viscosity,ionic conductivity,etc.)are cost-guaranteed,but undesired reactions would always occur and lead to battery degradation during long cycles.To promote the long-term cycle stability in a cost-effective way,this work constructs bidirectional fluorine-rich electrode/electrolyte interphase(EEI)by redistribution of solvents and electrochemical induction.The fluorinated effect with reasonable zoning planning restricts morphological disintegration,meanwhile,forms spatial confinement on cathode.In particular,the obtained cathode electrolyte interphase(CEI)gets the ample ability of Na^(+)transport,which benefits from the fluorinated organics arranged in the epitaxy and the hemi-carbonate content acting on the thickness.Thus,the electrochemical long cycling performance of F-NVPOFⅡF-CC full cells is significantly enhanced(the decay rate at 1 C per cycle is as low as 0.01%).Such a fluorine-rich EEI engineering is expected to take transitional layers against the degradation of cells and make ultra-long cycle batteries possible.

Combustion mechanism of fluorinated organic compound-modified nano-aluminum composite particles:Towards experimental and theoretical investigations

Fluorinated Organic Compounds(FOCs)are commonly used as modifiers for Aluminum(Al)powder to improve its ignition,combustion,and agglomeration characteristics.However,the effects of FOCs on combustion and inhibition mechanisms of agglomeration of Al powder are not well understood.In this paper,based on the experimental study of Fluorinated Graphite(FG)-modified Al matrix composite particles,the combustion and aggregation inhibition mechanisms of FOCs on Al particles were studied by the quantum chemical calculation at B3LYP/6-311+G(d,P)and G3//B3LYP/6-311+G(d,p)levels.The flame behavior and single particle burning behavior of FG-modified samples were compared through ignition experiments,and the characteristic spectra of Al related oxides of different samples in the initial ignition stage were captured.It is found that FG increases the burning intensity of Al composite samples significantly,while it decreases the emission intensity of Al secondary oxides.Quantum chemical calculation results show that the thermal decomposition intermediates of FOCs,namely C_(2)F_(4),can react with AlO and Al_(2)O,which weakens the characteristic emission intensity of AlO and Al_(2)O in the sample,and thus inhibits the formation of Al_(2)O_(3)in the combustion process.These results contribute to enriching the combustion dynamics model of Al-FOCs reaction system.

Recent Advances in the Electrochemical Defluorinative Transformations of C-F Bonds

Organic fluorine compounds are ubiquitous and pivotally important organic molecules,yet their activation and transformation have long been a formidable challenge due to the high energy and low reactivity of C-F bonds.Organic electrosynthesis,an environmentally benign synthetic method in organic chemistry,enables a myriad of chemical transformations without the need for external redox reagents.In recent years,organic electrochemistry has emerged as a powerful tool for achieving the activation and transformation of C-F bonds in fluorine-containing compounds.This review aims to succinctly recapitulate the latest advancements in the electrochemical defluorinative transformations of C-F bonds and to delve into the reaction design,mechanistic insights,and developmental prospects ofthese methods.