As environmental concerns from fossil fuel consumption intensify,large-scale energy storage becomes imperative for the integration of renewable sources like wind,hydro,and solar with the electrical grid.Redox flow bat...As environmental concerns from fossil fuel consumption intensify,large-scale energy storage becomes imperative for the integration of renewable sources like wind,hydro,and solar with the electrical grid.Redox flow batteries,particularly those employing organic molecules,are positioned as a key technology for this purpose.This review explores the growing field of symmetric organic redox flow batteries(ORFBs)within this context.Unlike traditional asymmetric designs based on unique active materials for each electrode,symmetric ORFBs involve a single bipolar species for both electrodes.This review highlights the benefits of a symmetric design,and categorizes five distinct classes of organic bipolar molecules used in both aqueous and non-aqueous solvents.By providing a comprehensive overview of their cell cycling and performance characteristics,the strengths and weaknesses of the diverse categories of bipolar molecules are highlighted for both solvent systems,as are opportunities for future development.This should guide new research directions and advance the development of practical symmetric ORFBs.展开更多
An exploratory multinuclear magnetic resonance(MR)and magnetic resonance imaging(MRI)study was performed on lithium-ion battery cells with ^(7)Li,^(19)F,and ^(1)H measurements.A variable field superconducting magnet w...An exploratory multinuclear magnetic resonance(MR)and magnetic resonance imaging(MRI)study was performed on lithium-ion battery cells with ^(7)Li,^(19)F,and ^(1)H measurements.A variable field superconducting magnet with a fixed frequency parallel-plate radiofrequency(RF)probe was employed in the study.The magnetic field was changed to set the resonance frequency of each nucleus to the fixed RF probe frequency of 33.7 MHz.Two cartridge-like lithium-ion cells,with graphite anodes and LiNi_(0.5)Mn_(0.3)Co_(0.2)O_(2)(NMC)cathodes,were interrogated.One cell was pristine,and one was charged to a cell voltage of 4.2 V.The results presented demonstrate the great potential of the variable field magnet approach in multinuclear measurement of lithium-ion batteries.These methods open the door for developing faster and simpler methods for detecting,quantifying,and interpreting MR and MRI data from lithium-ion and other batteries.展开更多
A symmetric all-organic non-aqueous redox flow-type battery was investigated employing the neutral small molecule radical 3-phenyl-1,5-di-p-tolylverdazyl,which can be reversibly oxidized and reduced in one-electron pr...A symmetric all-organic non-aqueous redox flow-type battery was investigated employing the neutral small molecule radical 3-phenyl-1,5-di-p-tolylverdazyl,which can be reversibly oxidized and reduced in one-electron processes,as the sole charge storage material.Cyclic voltammetry of the verdazyl radical in 0.5 M tetrabutylammonium hexa fluoro phosphate(TBAPF6)in acetonitrile revealed redox couples at-0.17 V and-1.15 V vs.Ag+/Ag,leading to a theoretical cell voltage of 0.98 V.From the dependence of peak currents on the square root of the scan rate,diffusion coefficients on the order of 4 x 10 6 cm2 s-1 were demonstrated.Cycling performance was assessed in a static cell employing a Tokoyuma AHA anion exchange membrane,with 0.04 M verdazyl as catholyte and anolyte in 0.5 M TBAPF6 in acetonitrile at a current density of 0.12 mA cm-2.Although coulombic efficiencies were good(94%-97%)throughout the experiment,the capacity faded gradually from high initial values of 93%of the theoretical discharge capacity to 35%by the 50th cycle.Voltage and energy efficiencies were 68%and 65%,respectively.Postcycling analysis by cyclic voltammetry revealed that decomposition of the active material with cycling is a leading cause of cell degradation.展开更多
基金Natural Sciences and Engineering Research Council(NSERC)of Canada(RGPIN-2022-03488)New Brunswick Innovation Foundation(NBIF)。
文摘As environmental concerns from fossil fuel consumption intensify,large-scale energy storage becomes imperative for the integration of renewable sources like wind,hydro,and solar with the electrical grid.Redox flow batteries,particularly those employing organic molecules,are positioned as a key technology for this purpose.This review explores the growing field of symmetric organic redox flow batteries(ORFBs)within this context.Unlike traditional asymmetric designs based on unique active materials for each electrode,symmetric ORFBs involve a single bipolar species for both electrodes.This review highlights the benefits of a symmetric design,and categorizes five distinct classes of organic bipolar molecules used in both aqueous and non-aqueous solvents.By providing a comprehensive overview of their cell cycling and performance characteristics,the strengths and weaknesses of the diverse categories of bipolar molecules are highlighted for both solvent systems,as are opportunities for future development.This should guide new research directions and advance the development of practical symmetric ORFBs.
基金BJB thanks the Canada Chairs program for a Research Chair in MRI of Materials[950e230894]an NSERC Discovery Grant[2015-6122]GRG thanks NSERC for a Discovery Grant[RGPIN-2017-06095].
文摘An exploratory multinuclear magnetic resonance(MR)and magnetic resonance imaging(MRI)study was performed on lithium-ion battery cells with ^(7)Li,^(19)F,and ^(1)H measurements.A variable field superconducting magnet with a fixed frequency parallel-plate radiofrequency(RF)probe was employed in the study.The magnetic field was changed to set the resonance frequency of each nucleus to the fixed RF probe frequency of 33.7 MHz.Two cartridge-like lithium-ion cells,with graphite anodes and LiNi_(0.5)Mn_(0.3)Co_(0.2)O_(2)(NMC)cathodes,were interrogated.One cell was pristine,and one was charged to a cell voltage of 4.2 V.The results presented demonstrate the great potential of the variable field magnet approach in multinuclear measurement of lithium-ion batteries.These methods open the door for developing faster and simpler methods for detecting,quantifying,and interpreting MR and MRI data from lithium-ion and other batteries.
基金supported by the Natural Sciences and Engineering Research Council (NSERC) of Canada (C. A. D.: DG, 04279 J. B. G.: DG, 435675 and S. M. B.: CGS D scholarship)+1 种基金support form the Canada Foundation for Innovation (CFI) the New Brunswick Innovation Foundation (NBIF)the University of New Brunswick. J. B. G. would like to thank the University of Western Ontario for support
文摘A symmetric all-organic non-aqueous redox flow-type battery was investigated employing the neutral small molecule radical 3-phenyl-1,5-di-p-tolylverdazyl,which can be reversibly oxidized and reduced in one-electron processes,as the sole charge storage material.Cyclic voltammetry of the verdazyl radical in 0.5 M tetrabutylammonium hexa fluoro phosphate(TBAPF6)in acetonitrile revealed redox couples at-0.17 V and-1.15 V vs.Ag+/Ag,leading to a theoretical cell voltage of 0.98 V.From the dependence of peak currents on the square root of the scan rate,diffusion coefficients on the order of 4 x 10 6 cm2 s-1 were demonstrated.Cycling performance was assessed in a static cell employing a Tokoyuma AHA anion exchange membrane,with 0.04 M verdazyl as catholyte and anolyte in 0.5 M TBAPF6 in acetonitrile at a current density of 0.12 mA cm-2.Although coulombic efficiencies were good(94%-97%)throughout the experiment,the capacity faded gradually from high initial values of 93%of the theoretical discharge capacity to 35%by the 50th cycle.Voltage and energy efficiencies were 68%and 65%,respectively.Postcycling analysis by cyclic voltammetry revealed that decomposition of the active material with cycling is a leading cause of cell degradation.
