The electrolyte directly contacts the essential parts of a lithium-ion battery,and as a result,the electrochemical properties of the electrolyte have a significant impact on the voltage platform,charge discharge capac...The electrolyte directly contacts the essential parts of a lithium-ion battery,and as a result,the electrochemical properties of the electrolyte have a significant impact on the voltage platform,charge discharge capacity,energy density,service life,and rate discharge performance.By raising the voltage at the charge/discharge plateau,the energy density of the battery is increased.However,this causes transition metal dissolution,irreversible phase changes of the cathode active material,and parasitic electrolyte oxidation reactions.This article presents an overview of these concerns to provide a clear explanation of the issues involved in the development of electrolytes for high-voltage lithium-ion batteries.Additionally,solidstate electrolytes enable various applications and will likely have an impact on the development of batteries with high energy densities.It is necessary to improve the high-voltage performance of electrolytes by creating solvents with high thermal stabilities and high voltage resistance and additives with superior film forming performance,multifunctional capabilities,and stable lithium salts.To offer suggestions for the future development of high-energy lithium-ion batteries,we conclude by offering our own opinions and insights on the current development of lithium-ion batteries.展开更多
DC stray current can cause severe corrosion on buried pipelines.In this study,firstly,we deduced the equation of DC stray current interference on pipelines.Next,the cathode boundary condition was discretized with pipe...DC stray current can cause severe corrosion on buried pipelines.In this study,firstly,we deduced the equation of DC stray current interference on pipelines.Next,the cathode boundary condition was discretized with pipe elements,and corresponding experiments were designed to validate the mathematical model.Finally,the numerical simulation program BEASY was used to study the corrosion effect of DC stray current that an auxiliary anode bed generated in an impressed current cathodic protection system.The effects of crossing angle,crossing distance,distance of the two pipelines,anode output current,depth,and soil resistivity were investigated.Our results indicate that pipeline crossing substantially affects the corrosion potential of both protected and unprotected pipelines.Pipeline crossing angles,crossing distances,and anode depths,our results suggest,have no significant influence.Decreasing anode output current or soil resistivity reduces pipeline corrosion gradually.A reduction of corrosion also occurs when the distance between two parallel pipelines increases.展开更多
In this work,molecular dynamics modeling was conducted to study hydrogen(H)-induced plastic deformation and cracking of polycrystalα-Fe.Under cyclic loading,the number of vacancies and the stress intensity increase w...In this work,molecular dynamics modeling was conducted to study hydrogen(H)-induced plastic deformation and cracking of polycrystalα-Fe.Under cyclic loading,the number of vacancies and the stress intensity increase with H atom concentration and the number of loading cycles.However,the effect of cyclic loading on cracking is not as significant as the increment of H concentration.As the H concentration increases,the dislocation generation and emission are enhanced in the{110}<111>slip system,but are inhibited in other slip systems.There is a critical H atom concentration,below which the plastic deformation ofα-Fe is facilitated by H atoms.When the critical H concentration is exceeded,the dislocation emission is inhibited by H atoms at grain boundaries,where the H atoms can pin dislocations,causing piling-up of the dislocations to generate a stress concentration.展开更多
基金supported by the Shandong Provincial Natural Science Foundation,China(No.ZR2019MEM014)。
文摘The electrolyte directly contacts the essential parts of a lithium-ion battery,and as a result,the electrochemical properties of the electrolyte have a significant impact on the voltage platform,charge discharge capacity,energy density,service life,and rate discharge performance.By raising the voltage at the charge/discharge plateau,the energy density of the battery is increased.However,this causes transition metal dissolution,irreversible phase changes of the cathode active material,and parasitic electrolyte oxidation reactions.This article presents an overview of these concerns to provide a clear explanation of the issues involved in the development of electrolytes for high-voltage lithium-ion batteries.Additionally,solidstate electrolytes enable various applications and will likely have an impact on the development of batteries with high energy densities.It is necessary to improve the high-voltage performance of electrolytes by creating solvents with high thermal stabilities and high voltage resistance and additives with superior film forming performance,multifunctional capabilities,and stable lithium salts.To offer suggestions for the future development of high-energy lithium-ion batteries,we conclude by offering our own opinions and insights on the current development of lithium-ion batteries.
文摘DC stray current can cause severe corrosion on buried pipelines.In this study,firstly,we deduced the equation of DC stray current interference on pipelines.Next,the cathode boundary condition was discretized with pipe elements,and corresponding experiments were designed to validate the mathematical model.Finally,the numerical simulation program BEASY was used to study the corrosion effect of DC stray current that an auxiliary anode bed generated in an impressed current cathodic protection system.The effects of crossing angle,crossing distance,distance of the two pipelines,anode output current,depth,and soil resistivity were investigated.Our results indicate that pipeline crossing substantially affects the corrosion potential of both protected and unprotected pipelines.Pipeline crossing angles,crossing distances,and anode depths,our results suggest,have no significant influence.Decreasing anode output current or soil resistivity reduces pipeline corrosion gradually.A reduction of corrosion also occurs when the distance between two parallel pipelines increases.
基金supported by National Natural Science Foundation of China(Nos.52374072,No.52004323)CNPC Innovation Foundation(No.2022DQ02-0502)+1 种基金Natural Science Foundation of Shandong Province(Nos.ZR2020ME094,ZR2019BEE006 and ZR2019MEE108)the Senior Foreign Expert Project Fund(No.G2022152003L).
文摘In this work,molecular dynamics modeling was conducted to study hydrogen(H)-induced plastic deformation and cracking of polycrystalα-Fe.Under cyclic loading,the number of vacancies and the stress intensity increase with H atom concentration and the number of loading cycles.However,the effect of cyclic loading on cracking is not as significant as the increment of H concentration.As the H concentration increases,the dislocation generation and emission are enhanced in the{110}<111>slip system,but are inhibited in other slip systems.There is a critical H atom concentration,below which the plastic deformation ofα-Fe is facilitated by H atoms.When the critical H concentration is exceeded,the dislocation emission is inhibited by H atoms at grain boundaries,where the H atoms can pin dislocations,causing piling-up of the dislocations to generate a stress concentration.
