Achieving simultaneous fast-charging capabilities and low-temperature adaptability in graphite-based lithium-ion batteries(LIBs)with an acceptable cycle life remains challenging.Herein,an ether-based electrolyte with ...Achieving simultaneous fast-charging capabilities and low-temperature adaptability in graphite-based lithium-ion batteries(LIBs)with an acceptable cycle life remains challenging.Herein,an ether-based electrolyte with temperature-adaptive Li^(+)solvation structure is designed for graphite,and stable Li^(+)/solvent co-intercalation has been achieved at subzero.As revealed by in-situ variable temperature(-20℃)X-ray diffraction(XRD),the poor compatibility of graphite in ether-based electrolyte at 25℃is mainly due to the continuous electrolyte decomposition and the in-plane rearrangement below0.5 V.Former results in a significant irreversible capacity,while latter maintains graphite in a prolonged state of extreme expansion,ultimately leading to its exfoliation and failure.In contrast,low temperature triggers the rearra ngement of Li^(+)solvation structu re with stronger Li^(+)/solvent binding energy and sho rter Li^(+)-O bond length,which is conducive for reversible Li^(+)/solvent co-intercalation and reducing the time of graphite in an extreme expansion state.In addition,the co-intercalation of solvents minimizes the interaction between Li-ions and host graphite,endowing graphite with fast diffusion kinetics.As expected,the graphite anode delivers about 84%of the capacity at room temperature at-20℃.Moreover,within6 min,about 83%,73%,and 43%of the capacity could be charged at 25,-20,and-40℃,respectively.展开更多
It is challenging for aqueous Zn-ion batteries(ZIBs)to achieve comparable low-temperature(low-T)performance due to the easy-frozen electrolyte and severe Zn dendrites.Herein,an aqueous electrolyte with a low freezing ...It is challenging for aqueous Zn-ion batteries(ZIBs)to achieve comparable low-temperature(low-T)performance due to the easy-frozen electrolyte and severe Zn dendrites.Herein,an aqueous electrolyte with a low freezing point and high ionic conductivity is proposed.Combined with molecular dynamics simulation and multi-scale interface analysis(time of flight secondary ion mass spectrometry threedimensional mapping and in-situ electrochemical impedance spectroscopy method),the temperature independence of the V_(2)O_(5)cathode and Zn anode is observed to be opposite.Surprisingly,dominated by the solvent structure of the designed electrolyte at low temperatures,vanadium dissolution/shuttle is significantly inhibited,and the zinc dendrites caused by this electrochemical crosstalk are greatly relieved,thus showing an abnormal temperature inversion effect.Through the disclosure and improvement of the above phenomena,the designed Zn||V_(2)O_(5)full cell delivers superior low-T performance,maintaining almost 99%capacity retention after 9500 cycles(working more than 2500 h)at-20°C.This work proposes a kind of electrolyte suitable for low-T ZIBs and reveals the inverse temperature dependence of the Zn anode,which might offer a novel perspective for the investigation of low-T aqueous battery systems.展开更多
Traditional O3-type Li-rich layered materials are attractive with ultra-high specific capacities,but suffering from inherent problems of voltage hysteresis and poor cycle performance.As an alternative,O2-type material...Traditional O3-type Li-rich layered materials are attractive with ultra-high specific capacities,but suffering from inherent problems of voltage hysteresis and poor cycle performance.As an alternative,O2-type materials show the potential to improve the oxygen redox reversibility and structural stability.However,their structure-performance relationship is still unclear.Here,we investigate the correlation between the Li component and dynamic chemical reversibility of O2-type Li-rich materials.By exploring the formation mechanism of a series of materials prepared by Na/Li exchange,we reveal that insufficient Li leads to an incomplete replacement,and the residual Na in the Li-layer would hinder the fast diffusion of Li^(+).Moreover,excessive Li induces the extraction of interlayer Li during the melting chemical reaction stage,resulting in a reduction in the valence of Mn,which leads to a severe Jahn-Teller effect.Structural detection confirms that the regulation of Li can improve the cycle stability of Li-rich materials and suppress the trend of voltage fading.The reversible phase evolution observed in in-situ X-ray diffraction confirms the excellent structural stability of the optimized material,which is conducive to capacity retention.This work highlights the significance of modulating dynamic electrochemical performance through the intrinsic structure.展开更多
Co-free Li-rich layered oxide cathodes have drawn much attention owing to their low cost and high energy density.Nevertheless,anion oxidation of oxygen leads to oxygen peroxidation during the first charging process,wh...Co-free Li-rich layered oxide cathodes have drawn much attention owing to their low cost and high energy density.Nevertheless,anion oxidation of oxygen leads to oxygen peroxidation during the first charging process,which leads to co-migration of transition metal ions and oxygen vacancies,causing structural instability.In this work,we propose a pre-activation strategy driven by chemical impregnation to modulate the chemical state of surface lattice oxygen,thus regulating the structural and electrochemical properties of the cathodes.In-situ X-ray diffraction confirms that materials based on activated oxygen configuration have higher structural stability.More importantly,this novel efficient strategy endows the cathodes having a lower surface charge transfer barrier and higher Li+transfer kinetics characteristic and ameliorates its inherent issues.The optimized cathode exhibits excellent electrochemical performance:after 300 cycles,high capacity(from 238 m Ah g^(-1)to 193 m Ah g^(-1)at 1 C)and low voltage attenuation(168 mV)are obtained.Overall,this modulated surface lattice oxygen strategy improves the electrochemical activity and structural stability,providing an innovative idea to obtain high-capacity Co-free Li-rich cathodes for next-generation Li-ion batteries.展开更多
Achieving an in-depth understanding of the nexus between temperature and phase transitions is paramount for advancing the electrochemical efficiency of aqueous zinc ion batteries.Yet,the intricacies of electrochemical...Achieving an in-depth understanding of the nexus between temperature and phase transitions is paramount for advancing the electrochemical efficiency of aqueous zinc ion batteries.Yet,the intricacies of electrochemical interactions,particularly those associated with the structural evolution over extended periods,remain enigmatic.In this research,we leverage V_(2)O_(5) as an initial structural model of crystals to demystify the kinetics of electrode reactions and the decay mechanism of global electrochemical degradation by meticulously controlling the crystal defects via applying different mechanical grounding intensities.It is noted that the grounding V_(2)O_(5)(GVO)can exhibit a stable crystal structure that suppresses the dissolution/shuttling of vanadium and mitigates Zn anodes by-products caused by electrochemical processes.Thus,the GVO is utilized as the cathode material,achieving excellent Zn storage capacity at both room temperature and low temperatures,e.g.,380 and 246 mA h g^(−1) at room temperature and−20℃,respectively.Remarkably,the GVO cathode retains a specific capacity of 160 mA h g^(−1) with a capacity retention rate of 99%after 1500 cycles at−20℃ and 1 A g^(−1).This work provides a novel insight into the electrochemical crosstalk behavior of aqueous zinc-ion batteries(AZIBs)in a wide range of temperatures.展开更多
基金financially supported by the National Natural Science Foundation of China(52372191)the Natural Science Foundation of Fujian Province(2023J05047)+1 种基金the Natural Science Foundation of Xiamen,China(3502Z202372036)the support of the High-Performance Computing Center(HPCC)at Harbin Institute of Technology on first-principles calculations.
文摘Achieving simultaneous fast-charging capabilities and low-temperature adaptability in graphite-based lithium-ion batteries(LIBs)with an acceptable cycle life remains challenging.Herein,an ether-based electrolyte with temperature-adaptive Li^(+)solvation structure is designed for graphite,and stable Li^(+)/solvent co-intercalation has been achieved at subzero.As revealed by in-situ variable temperature(-20℃)X-ray diffraction(XRD),the poor compatibility of graphite in ether-based electrolyte at 25℃is mainly due to the continuous electrolyte decomposition and the in-plane rearrangement below0.5 V.Former results in a significant irreversible capacity,while latter maintains graphite in a prolonged state of extreme expansion,ultimately leading to its exfoliation and failure.In contrast,low temperature triggers the rearra ngement of Li^(+)solvation structu re with stronger Li^(+)/solvent binding energy and sho rter Li^(+)-O bond length,which is conducive for reversible Li^(+)/solvent co-intercalation and reducing the time of graphite in an extreme expansion state.In addition,the co-intercalation of solvents minimizes the interaction between Li-ions and host graphite,endowing graphite with fast diffusion kinetics.As expected,the graphite anode delivers about 84%of the capacity at room temperature at-20℃.Moreover,within6 min,about 83%,73%,and 43%of the capacity could be charged at 25,-20,and-40℃,respectively.
基金financially supported by the National Natural Science Foundation of China(52372191)the Natural Science Foundation of Xiamen,China(3502Z202372036)+1 种基金the China Postdoctoral Science Foundation(2022TQ0282)the support of the High-Performance Computing Center(HPCC)at Harbin Institute of Technology on first-principles calculations。
文摘It is challenging for aqueous Zn-ion batteries(ZIBs)to achieve comparable low-temperature(low-T)performance due to the easy-frozen electrolyte and severe Zn dendrites.Herein,an aqueous electrolyte with a low freezing point and high ionic conductivity is proposed.Combined with molecular dynamics simulation and multi-scale interface analysis(time of flight secondary ion mass spectrometry threedimensional mapping and in-situ electrochemical impedance spectroscopy method),the temperature independence of the V_(2)O_(5)cathode and Zn anode is observed to be opposite.Surprisingly,dominated by the solvent structure of the designed electrolyte at low temperatures,vanadium dissolution/shuttle is significantly inhibited,and the zinc dendrites caused by this electrochemical crosstalk are greatly relieved,thus showing an abnormal temperature inversion effect.Through the disclosure and improvement of the above phenomena,the designed Zn||V_(2)O_(5)full cell delivers superior low-T performance,maintaining almost 99%capacity retention after 9500 cycles(working more than 2500 h)at-20°C.This work proposes a kind of electrolyte suitable for low-T ZIBs and reveals the inverse temperature dependence of the Zn anode,which might offer a novel perspective for the investigation of low-T aqueous battery systems.
基金the National Natural Science Foundation of China(21673064 and 51902072)the Heilongjiang Touyan Team(HITTY-20190033)+2 种基金the Fundamental Research Funds for the Central Universities(HIT.NSRIF.2019040 and 2019041)the State Key Laboratory of Urban Water Resource and Environment(Harbin Institute of Technology)(2020 DX11)the Heilongjiang postdoctoral financial assistance(LBH-Z19055)。
文摘Traditional O3-type Li-rich layered materials are attractive with ultra-high specific capacities,but suffering from inherent problems of voltage hysteresis and poor cycle performance.As an alternative,O2-type materials show the potential to improve the oxygen redox reversibility and structural stability.However,their structure-performance relationship is still unclear.Here,we investigate the correlation between the Li component and dynamic chemical reversibility of O2-type Li-rich materials.By exploring the formation mechanism of a series of materials prepared by Na/Li exchange,we reveal that insufficient Li leads to an incomplete replacement,and the residual Na in the Li-layer would hinder the fast diffusion of Li^(+).Moreover,excessive Li induces the extraction of interlayer Li during the melting chemical reaction stage,resulting in a reduction in the valence of Mn,which leads to a severe Jahn-Teller effect.Structural detection confirms that the regulation of Li can improve the cycle stability of Li-rich materials and suppress the trend of voltage fading.The reversible phase evolution observed in in-situ X-ray diffraction confirms the excellent structural stability of the optimized material,which is conducive to capacity retention.This work highlights the significance of modulating dynamic electrochemical performance through the intrinsic structure.
基金the National Natural Science Foundation of China(51902072 and 22075062)the Heilongjiang Touyan Team(HITTY-20190033)+2 种基金the Heilongjiang Province“hundred million”project science and technology major special projects(2019ZX09A02)the State Key Laboratory of Urban Water Resource and Environment(Harbin Institute of Technology No.2020DX11)the Fundamental Research Funds for the Central Universities(FRFCU5710051922)。
文摘Co-free Li-rich layered oxide cathodes have drawn much attention owing to their low cost and high energy density.Nevertheless,anion oxidation of oxygen leads to oxygen peroxidation during the first charging process,which leads to co-migration of transition metal ions and oxygen vacancies,causing structural instability.In this work,we propose a pre-activation strategy driven by chemical impregnation to modulate the chemical state of surface lattice oxygen,thus regulating the structural and electrochemical properties of the cathodes.In-situ X-ray diffraction confirms that materials based on activated oxygen configuration have higher structural stability.More importantly,this novel efficient strategy endows the cathodes having a lower surface charge transfer barrier and higher Li+transfer kinetics characteristic and ameliorates its inherent issues.The optimized cathode exhibits excellent electrochemical performance:after 300 cycles,high capacity(from 238 m Ah g^(-1)to 193 m Ah g^(-1)at 1 C)and low voltage attenuation(168 mV)are obtained.Overall,this modulated surface lattice oxygen strategy improves the electrochemical activity and structural stability,providing an innovative idea to obtain high-capacity Co-free Li-rich cathodes for next-generation Li-ion batteries.
基金supported by the Natural Science Foundation of Xiamen, China (3502Z202372036)the National Natural Science Foundation of China (52372191, 52073286 (to CZ Lu), 22275185 (to CZ Lu))+4 种基金the Scientific Research Funds of Huaqiao University (20221XD027, 20221XD045)the Xiamen Institute of Rare Earth Materials Haixi Institutes (XMIREM)the Autonomously Deployment Project (2023GG01 (to CZ Lu))the Fujian Science & Technology Innovation Laboratory for Optoelectronic Information of China (2021ZZ115 (to CZ Lu))the China Postdoctoral Science Foundation (2022TQ0282)。
文摘Achieving an in-depth understanding of the nexus between temperature and phase transitions is paramount for advancing the electrochemical efficiency of aqueous zinc ion batteries.Yet,the intricacies of electrochemical interactions,particularly those associated with the structural evolution over extended periods,remain enigmatic.In this research,we leverage V_(2)O_(5) as an initial structural model of crystals to demystify the kinetics of electrode reactions and the decay mechanism of global electrochemical degradation by meticulously controlling the crystal defects via applying different mechanical grounding intensities.It is noted that the grounding V_(2)O_(5)(GVO)can exhibit a stable crystal structure that suppresses the dissolution/shuttling of vanadium and mitigates Zn anodes by-products caused by electrochemical processes.Thus,the GVO is utilized as the cathode material,achieving excellent Zn storage capacity at both room temperature and low temperatures,e.g.,380 and 246 mA h g^(−1) at room temperature and−20℃,respectively.Remarkably,the GVO cathode retains a specific capacity of 160 mA h g^(−1) with a capacity retention rate of 99%after 1500 cycles at−20℃ and 1 A g^(−1).This work provides a novel insight into the electrochemical crosstalk behavior of aqueous zinc-ion batteries(AZIBs)in a wide range of temperatures.
