The reaction rate constant is a crucial kinetic parameter that governs the charge and discharge performance of batteries,particularly in high-rate and thick-electrode applications.However,conventional estimation or fi...The reaction rate constant is a crucial kinetic parameter that governs the charge and discharge performance of batteries,particularly in high-rate and thick-electrode applications.However,conventional estimation or fitting methods often overestimate the charge transfer overpotential,leading to substantial errors in reaction rate constant measurements.These inaccuracies hinder the accurate prediction of voltage profiles and overall cell performance.In this study,we propose the characteristic time-decomposed overpotential(CTDO)method,which employs a single-layer particle electrode(SLPE)structure to eliminate interference overpotentials.By leveraging the distribution of relaxation times(DRT),our method effectively isolates the characteristic time of the charge transfer process,enabling a more precise determination of the reaction rate constant.Simulation results indicate that our approach reduces measurement errors to below 2%,closely aligning with theoretical values.Furthermore,experimental validation demonstrates an 80% reduction in error compared to the conventional galvanostatic intermittent titration technique(GITT)method.Overall,this study provides a novel voltage-based approach for determining the reaction rate constant,enhancing the applicability of theoretical analysis in electrode structural design and facilitating rapid battery optimization.展开更多
Two-dimensional(2D)transition-metal selenides,espe-cially MoSe_(2),is considered to be an excellent alternative electrocatalyst for the hydrogen evolution reaction(HER).However,it still features high overpotential in ...Two-dimensional(2D)transition-metal selenides,espe-cially MoSe_(2),is considered to be an excellent alternative electrocatalyst for the hydrogen evolution reaction(HER).However,it still features high overpotential in HER due to the low density of active sites,which limits its practical application.Herein,the hydrogen evolution reaction activity of MoSe_(2)is enhanced by the incorporation of metal-cation,tungsten,which succeeds in taking the place of Mo in the lattice of MoSe_(2),inducing the spacing expansion and bringing new flexural edges to serve as active sites.In addition,the incorporated metal also facil-itates electron transport from Mo active center toward W and Se atoms with auspicious hydrogen adsorption prop-erties.展开更多
Lithium carbon fluorides(Li/CFx)primary batteries are of highly interests due to their high specific energy and power densities.The shelf life is one of the major concerns when they are used as backup power,emergency ...Lithium carbon fluorides(Li/CFx)primary batteries are of highly interests due to their high specific energy and power densities.The shelf life is one of the major concerns when they are used as backup power,emergency power and storage power in landers,manned spacecraft or military applications.In this work,real-time storage tests are carried out for both energy-type and power-type Li/CFx pouch batteries at 25℃.Accelerated storage tests are performed at elevated temperature of 55℃.The electrochemical tests are conducted throughout the aging period of 0-365 days for various batteries to study the effects of temperature on both type of batteries.The observed electrochemical behaviors are explained with the evidences from multiple characterizations for post-tested samples.展开更多
基金supported by the National Key R&D Program of China 2022YFB2404300the National Natural Science Foundation of China U22B2069the China Postdoctoral Science Foundation 2024M761006。
文摘The reaction rate constant is a crucial kinetic parameter that governs the charge and discharge performance of batteries,particularly in high-rate and thick-electrode applications.However,conventional estimation or fitting methods often overestimate the charge transfer overpotential,leading to substantial errors in reaction rate constant measurements.These inaccuracies hinder the accurate prediction of voltage profiles and overall cell performance.In this study,we propose the characteristic time-decomposed overpotential(CTDO)method,which employs a single-layer particle electrode(SLPE)structure to eliminate interference overpotentials.By leveraging the distribution of relaxation times(DRT),our method effectively isolates the characteristic time of the charge transfer process,enabling a more precise determination of the reaction rate constant.Simulation results indicate that our approach reduces measurement errors to below 2%,closely aligning with theoretical values.Furthermore,experimental validation demonstrates an 80% reduction in error compared to the conventional galvanostatic intermittent titration technique(GITT)method.Overall,this study provides a novel voltage-based approach for determining the reaction rate constant,enhancing the applicability of theoretical analysis in electrode structural design and facilitating rapid battery optimization.
基金financially supported by the National Natural Science Foundation of China (Nos.52071226, 51872193 and 5192500409)the Natural Science Foundation of Jiangsu Province (Nos.BK20190827 and BK20181168)
文摘Two-dimensional(2D)transition-metal selenides,espe-cially MoSe_(2),is considered to be an excellent alternative electrocatalyst for the hydrogen evolution reaction(HER).However,it still features high overpotential in HER due to the low density of active sites,which limits its practical application.Herein,the hydrogen evolution reaction activity of MoSe_(2)is enhanced by the incorporation of metal-cation,tungsten,which succeeds in taking the place of Mo in the lattice of MoSe_(2),inducing the spacing expansion and bringing new flexural edges to serve as active sites.In addition,the incorporated metal also facil-itates electron transport from Mo active center toward W and Se atoms with auspicious hydrogen adsorption prop-erties.
基金This work was supported by Governmental Program(050502).
文摘Lithium carbon fluorides(Li/CFx)primary batteries are of highly interests due to their high specific energy and power densities.The shelf life is one of the major concerns when they are used as backup power,emergency power and storage power in landers,manned spacecraft or military applications.In this work,real-time storage tests are carried out for both energy-type and power-type Li/CFx pouch batteries at 25℃.Accelerated storage tests are performed at elevated temperature of 55℃.The electrochemical tests are conducted throughout the aging period of 0-365 days for various batteries to study the effects of temperature on both type of batteries.The observed electrochemical behaviors are explained with the evidences from multiple characterizations for post-tested samples.
