Lithium-ion batteries(LIBs)are pivotal in modern energy storage systems,yet their safety and longevity are critically threatened by several abuses.The over-discharge is overlooked in extreme operational conditions.Ove...Lithium-ion batteries(LIBs)are pivotal in modern energy storage systems,yet their safety and longevity are critically threatened by several abuses.The over-discharge is overlooked in extreme operational conditions.Over-discharge in LIBs poses significant threats to performance and safety,inducing irreversible structural and electrochemical degradation.Key mechanisms include solid electrolyte interphase(SEI)layer breakdown,copper dissolution,and dendrite-induced internal short circuits,which accelerate capacity fade and thermal runaway risks.This review systematically analyzes these degradation pathways and evaluates mitigation strategies,such as voltage cutoff circuits,advanced battery management systems(BMS),and innovative protection strategies at the material level,like prelithiation and artificial SEI layers.The work also identifies gaps in current research,advocating for improved predictive models and industrial-scale solutions to address over-discharge challenges in next-generation energy storage systems.展开更多
4,7-Bisphenyl-1,10-phenanthroline(BPhen)is a promising electron transport material(ETM)and has been widely used in organic light-emitting diodes(OLEDs)because of the large electron mobility and easy fabrication proces...4,7-Bisphenyl-1,10-phenanthroline(BPhen)is a promising electron transport material(ETM)and has been widely used in organic light-emitting diodes(OLEDs)because of the large electron mobility and easy fabrication process.However,its low glass transition temperature would lead to poor device stability.In the past decades,various attempts have been carried out to improve its thermal stability though always be accomplished by the reduced electron mobility.Here,we present a molecular engineering to modulate the properties of BPhen,and through which,a versatile BPhen derivative(4,7-bis(naphthaleneb-yl)-1,10-phenanthroline,b-BNPhen)with high thermal stability(glass transition temperature=111.9℃),large electron mobility(7.8×10-4 cm2/(V s)under an electrical field of 4.5×105 V/cm)and excellent n-doping ability with an air-stable metal of Ag is developed and used as multifunctional layers to improve the efficiency and enhance the stability of OLEDs.This work elucidates the great importance of our molecular engineering methodology and device structure optimization strategy,unlocking the potential of 1,10-phenanthroline derivatives towards practical applications.展开更多
基金supported by the National Natural Science Foundation of China(Nos.U21A20170 and 22279070)National Key Research and Development Program of China(Nos.2021YFB2501900 and 2019YFA0705703)+3 种基金Beijing Natural Science Foundation(No.L242005)Engineering Research Center of Alternative Energy Materials&Devices,Ministry of Education(No.AEMDKF202502)the Key Laboratory of Green Extraction&Efficient Utilization of Light Rare-Earth Resources,Ministry of Education(No.KLRE-KF-005)Key Laboratory of Ionic Rare Earth Resources and Environment,Ministry of Natural Resources of the People’s Republic of China(No.2024IRERE301).
文摘Lithium-ion batteries(LIBs)are pivotal in modern energy storage systems,yet their safety and longevity are critically threatened by several abuses.The over-discharge is overlooked in extreme operational conditions.Over-discharge in LIBs poses significant threats to performance and safety,inducing irreversible structural and electrochemical degradation.Key mechanisms include solid electrolyte interphase(SEI)layer breakdown,copper dissolution,and dendrite-induced internal short circuits,which accelerate capacity fade and thermal runaway risks.This review systematically analyzes these degradation pathways and evaluates mitigation strategies,such as voltage cutoff circuits,advanced battery management systems(BMS),and innovative protection strategies at the material level,like prelithiation and artificial SEI layers.The work also identifies gaps in current research,advocating for improved predictive models and industrial-scale solutions to address over-discharge challenges in next-generation energy storage systems.
基金supported by the National Key Basic Research and Development Program of China(2017YFA0204501,2016YFB0400702 and 2016YFB0401003)the National Natural Science Foundation of China(51525304 and 61890942)the Fundamental Research Funds for the Central Universities.
文摘4,7-Bisphenyl-1,10-phenanthroline(BPhen)is a promising electron transport material(ETM)and has been widely used in organic light-emitting diodes(OLEDs)because of the large electron mobility and easy fabrication process.However,its low glass transition temperature would lead to poor device stability.In the past decades,various attempts have been carried out to improve its thermal stability though always be accomplished by the reduced electron mobility.Here,we present a molecular engineering to modulate the properties of BPhen,and through which,a versatile BPhen derivative(4,7-bis(naphthaleneb-yl)-1,10-phenanthroline,b-BNPhen)with high thermal stability(glass transition temperature=111.9℃),large electron mobility(7.8×10-4 cm2/(V s)under an electrical field of 4.5×105 V/cm)and excellent n-doping ability with an air-stable metal of Ag is developed and used as multifunctional layers to improve the efficiency and enhance the stability of OLEDs.This work elucidates the great importance of our molecular engineering methodology and device structure optimization strategy,unlocking the potential of 1,10-phenanthroline derivatives towards practical applications.
