Nickel-rich LiNi_(1-x-y)Co_(x)Mn_(y)O_(2)(NCM,1-x-y≥0.6)is known as a promising cathode material for lithium-ion batteries since its superiority of high voltage and large capacity.However,polycrystalline Ni-rich NCMs...Nickel-rich LiNi_(1-x-y)Co_(x)Mn_(y)O_(2)(NCM,1-x-y≥0.6)is known as a promising cathode material for lithium-ion batteries since its superiority of high voltage and large capacity.However,polycrystalline Ni-rich NCMs suffer from poor cycle stability,limiting its further application.Herein,single crystal and polycrystalline LiNi_(0.84)Co_(0.07)Mn_(0.09)O_(2)cathode materials are compared to figure out the relation of the morphology and the electrochemical storage performance.According to the Li^(+)diffusion coefficient,the lower capacity of single crystal samples is mainly ascribed to the limited Li+diffusion in the large bulk.In situ XRD illustrates that the polycrystalline and single crystal NCMs show a virtually identical manner and magnitude in lattice contraction and expansion during cycling.Also,the electrochemically active surface area(ECSA)measurement is employed in lithium-ion battery study for the first time,and these two cathodes show huge discrepancy in the ECSA after the initial cycle.These results suggest that the single crystal sample exhibits reduced cracking,surface side reaction,and Ni/Li mixing but suffers the lower Li^(+)diffusion kinetics.This work offers a view of how the morphology of Ni-rich NCM effects the electrochemical performance,which is instructive for developing a promising strategy to achieve good rate performance and excellent cycling stability.展开更多
The rapid advancement in electronic devices,electric vehicles,and grid storage stations have lead to a high demand for energy storage devices with enhanced power and energy densities as well as extended lifespans.Lith...The rapid advancement in electronic devices,electric vehicles,and grid storage stations have lead to a high demand for energy storage devices with enhanced power and energy densities as well as extended lifespans.Lithium ion hybrid capacitors are constructed with battery-type anodes and capacitor-type cathodes,which enables the direct integration of the high energy from lithium ion batteries and high power and long lifetime from supercapacitors,making lithium ion hybrid capacitor one of the most promising energy storage devices.In the past two decades,tremendous efforts have been put into the search for suitable battery-type anode materials with improved Faradaic reaction kinetics so that it can match with the fast non-Faradaic charging rate of the capacitive cathodes.This review aims to provide an up-to-date and comprehensive summary of the battery-type anode materials for high-performance lithium ion hybrid capacitors.To date,a large variety of battery-type anode materials have been explored with smart material design strategies,such as carbonaceous materials,metal oxides,alloys,sulfides,nitirdes,and Mxenes,etc.,which will be discussed in detail.A perspective to the challenges and future developing trends of lithium ion hybrid capacitors is proposed to close.展开更多
Owing to their high theoretical specific capacity and low cost, lithium- and manganese-rich layered oxide (LMR) cathode materials are receiving increasing attention for application in lithium-ion batteries. However, p...Owing to their high theoretical specific capacity and low cost, lithium- and manganese-rich layered oxide (LMR) cathode materials are receiving increasing attention for application in lithium-ion batteries. However, poor lithium ion and electron transport kinetics plus side effects of anion and cation redox reactions hamper power performance and stability of the LMRs. In this study, LMR Li_(1.2)Mn_(0.6)Ni_(0.2)O_(2) was modified by phosphorus (P)-doping to increase Li+ conductivity in the bulk material. This was achieved by increasing the interlayer spacing of the lithium layer, electron transport and structural stability, resulting in improvement of the rate and safety performance. P^(5+) doping increased the distance between the (003) crystal planes from ~0.474 nm to 0.488 nm and enhanced the structural stability by forming strong covalent bonds with oxygen atoms, resulting in an improved rate performance (capacity retention from 38% to 50% at 0.05 C to 5 C) and thermal stability (50% heat release compared with pristine material). First-principles calculations showed the P-doping makes the transfer of excited electrons from the valence band to conduction band easier and P can form a strong covalent bond helping to stabilize material structure. Furthermore, the solid-state electrolyte modified P5+ doped LMR showed an improved cycle performance for up to 200 cycles with capacity retention of 90.5% and enhanced initial coulombic efficiency from 68.5% (pristine) or 81.7% (P-doped LMR) to 88.7%.展开更多
Benefiting from the advantageous features of structural diversity and resource renewability,organic electroactive compounds are considered as attractive cathode materials for aqueous Zn-ion batteries(ZIBs).In this rev...Benefiting from the advantageous features of structural diversity and resource renewability,organic electroactive compounds are considered as attractive cathode materials for aqueous Zn-ion batteries(ZIBs).In this review,we discuss the recent developments of organic electrode materials for aqueous ZIBs.Although the proton(H^(+))storage chemistry in aqueous Zn-organic batteries has triggered an overwhelming literature surge in recent years,this topic remains controversial.Therefore,our review focuses on this significant issue and summarizes the reported electrochemical mechanisms,including pure Zn^(2+)intercalation,pure H^(+)storage,and H^(+)/Zn^(2+)co-storage.Moreover,the impact of H^(+)storage on the electrochemical performance of aqueous ZIBs is discussed systematically.Given the significance of H^(+)storage,we also highlight the relevant characterization methods employed.Finally,perspectives and directions on further understanding the charge storage mechanisms of organic materials are outlined.We hope that this review will stimulate more attention on the H^(+)storage chemistry of organic electrode materials to advance our understanding and further its application.展开更多
Electrolytes hold the key to realizing reliable zinc(Zn)anodes.Divergent organic molecules have been proven effective in stabilizing Zn anodes;however,irrational comparisons exist due to the uncontrolled molecular wei...Electrolytes hold the key to realizing reliable zinc(Zn)anodes.Divergent organic molecules have been proven effective in stabilizing Zn anodes;however,irrational comparisons exist due to the uncontrolled molecular weights and functional group amounts.In this work,two“isomeric molecules”:1,2-dimethoxyethane(DME)and 1-methoxy-2-propanol(PM),with identical molecular weights but different functional groups,have been studied as co-solvents in electrolytes,which have delivered distinct electrochemical performance.Experimental and simulative study indicates the dipole moment induced by the hydroxyl groups in PM(higher molecular polarity than ether groups in DME)reconstructs the space charge region,enhances the concentration of Zn^(2+)in the vicinity of Zn anodes,and in-situ derives different solid electrolyte interphase(SEI)models and electrode-electrolyte interfaces,resulting in exceptional cycling stability.Remarkably,the Zn||Cu cell with PM worked over 2000 cycles with high Coulombic efficiency(CE)of 99.7%.The Zn||Zn symmetric cell cycled over 2000 h at 1 mA·cm^(−2),and showed excellent stability at an ultrahigh current density of 10 mA·cm^(−2)and capacity of 20 mAh·cm^(−2)over 200 h(depth of discharge,DOD of 70%).The Zn||sodium vanadate pouch cell with a high mass loading of 6.3 mg·cm^(−2)and a high capacity of 24 mAh demonstrates superior cyclability after 570 h.This work can be a good starting point to provide reliable guidance on electrolyte design for practical aqueous Zn batteries.展开更多
Non-flow aqueous zinc-bromine batteries without auxiliary components(e.g.,pumps,pipes,storage tanks)and ion-selective membranes represent a cost-effective and promising technology for large-scale energy storage.Unfort...Non-flow aqueous zinc-bromine batteries without auxiliary components(e.g.,pumps,pipes,storage tanks)and ion-selective membranes represent a cost-effective and promising technology for large-scale energy storage.Unfortunately,they generally suffer from serious diffusion and shuttle of polybromide(Br^(-),Br^(3-))due to the weak physical adsorption between soluble polybromide and host carbon materials,which results in low energy efficiency and poor cycling stability.Here,we develop a novel self-capture organic bromine material(1,10-bis[3-(trimethylammonio)propyl]-4,40-bipyridinium bromine,NVBr4)to successfully realize reversible solid complexation of bromide components for stable non-flow zinc-bromine battery applications.The quaternary ammonium groups(NV^(4+)ions)can effectively capture the soluble polybromide species based on strong chemical interaction and realize reversible solid complexation confined within the porous electrodes,which transforms the conventional“liquid-liquid”conversion of soluble bromide components into“liquid-solid”model and effectively suppresses the shuttle effect.Thereby,the developed non-flow zinc-bromide battery provides an outstanding voltage platform at 1.7 V with a notable specific capacity of 325 mAh g^(-1)NVBr4(1 A g^(-1)),excellent rate capability(200 mAh g^(-1)NVBr4 at 20 A g^(-1)),outstanding energy density of 469.6 Wh kg^(-1)and super-stable cycle life(20,000 cycles with 100%Coulombic efficiency),which outperforms most of reported zinc-halogen batteries.Further mechanism analysis and DFT calculations demonstrate that the chemical interaction of quaternary ammonium groups and bromide species is the main reason for suppressing the shuttle effect.The developed strategy can be extended to other halogen batteries to obtain stable charge storage.展开更多
基金supported by the National Natural Science Foundation of China(Nos.51872157,52072208)Shenzhen Technical Plan Project(JCYJ20170817161753629)+1 种基金Fundamental Research Project of Shenzhen(No.JCYJ20190808153609561)Local Innovative and Research Teams Project of Guangdong Pearl River Talents Program(2017BT01N111).
文摘Nickel-rich LiNi_(1-x-y)Co_(x)Mn_(y)O_(2)(NCM,1-x-y≥0.6)is known as a promising cathode material for lithium-ion batteries since its superiority of high voltage and large capacity.However,polycrystalline Ni-rich NCMs suffer from poor cycle stability,limiting its further application.Herein,single crystal and polycrystalline LiNi_(0.84)Co_(0.07)Mn_(0.09)O_(2)cathode materials are compared to figure out the relation of the morphology and the electrochemical storage performance.According to the Li^(+)diffusion coefficient,the lower capacity of single crystal samples is mainly ascribed to the limited Li+diffusion in the large bulk.In situ XRD illustrates that the polycrystalline and single crystal NCMs show a virtually identical manner and magnitude in lattice contraction and expansion during cycling.Also,the electrochemically active surface area(ECSA)measurement is employed in lithium-ion battery study for the first time,and these two cathodes show huge discrepancy in the ECSA after the initial cycle.These results suggest that the single crystal sample exhibits reduced cracking,surface side reaction,and Ni/Li mixing but suffers the lower Li^(+)diffusion kinetics.This work offers a view of how the morphology of Ni-rich NCM effects the electrochemical performance,which is instructive for developing a promising strategy to achieve good rate performance and excellent cycling stability.
基金This work was supported by National Key Basic Research Program of China(No.2014CB932400)Joint Fund of the National Natural Science Foundation of China(No.U1401243)+2 种基金National Nature Science Foundation of China(No.51232005,51571144)Shenzhen Tech-nical Plan Project(No.JCYJ20150529164918735,JCYJ20170412170911187,KQJSCX20160226191136)Guangdong Technical Plan Project(No.2015T X01N011).
文摘The rapid advancement in electronic devices,electric vehicles,and grid storage stations have lead to a high demand for energy storage devices with enhanced power and energy densities as well as extended lifespans.Lithium ion hybrid capacitors are constructed with battery-type anodes and capacitor-type cathodes,which enables the direct integration of the high energy from lithium ion batteries and high power and long lifetime from supercapacitors,making lithium ion hybrid capacitor one of the most promising energy storage devices.In the past two decades,tremendous efforts have been put into the search for suitable battery-type anode materials with improved Faradaic reaction kinetics so that it can match with the fast non-Faradaic charging rate of the capacitive cathodes.This review aims to provide an up-to-date and comprehensive summary of the battery-type anode materials for high-performance lithium ion hybrid capacitors.To date,a large variety of battery-type anode materials have been explored with smart material design strategies,such as carbonaceous materials,metal oxides,alloys,sulfides,nitirdes,and Mxenes,etc.,which will be discussed in detail.A perspective to the challenges and future developing trends of lithium ion hybrid capacitors is proposed to close.
基金This work was supported by the National Natural Science Foundation of China(U1564205)the Project of Construction of Innovative Teams and Teacher Career Development for Universities and Colleges under the Beijing Municipality(IDHT20180508).Naser Tavajohi acknowledges financial support from the Kempe Foundation.
文摘Owing to their high theoretical specific capacity and low cost, lithium- and manganese-rich layered oxide (LMR) cathode materials are receiving increasing attention for application in lithium-ion batteries. However, poor lithium ion and electron transport kinetics plus side effects of anion and cation redox reactions hamper power performance and stability of the LMRs. In this study, LMR Li_(1.2)Mn_(0.6)Ni_(0.2)O_(2) was modified by phosphorus (P)-doping to increase Li+ conductivity in the bulk material. This was achieved by increasing the interlayer spacing of the lithium layer, electron transport and structural stability, resulting in improvement of the rate and safety performance. P^(5+) doping increased the distance between the (003) crystal planes from ~0.474 nm to 0.488 nm and enhanced the structural stability by forming strong covalent bonds with oxygen atoms, resulting in an improved rate performance (capacity retention from 38% to 50% at 0.05 C to 5 C) and thermal stability (50% heat release compared with pristine material). First-principles calculations showed the P-doping makes the transfer of excited electrons from the valence band to conduction band easier and P can form a strong covalent bond helping to stabilize material structure. Furthermore, the solid-state electrolyte modified P5+ doped LMR showed an improved cycle performance for up to 200 cycles with capacity retention of 90.5% and enhanced initial coulombic efficiency from 68.5% (pristine) or 81.7% (P-doped LMR) to 88.7%.
基金We acknowledge the financial support from National Natural Science Foundation of China(22109134)Guangdong Basic and Applied Basic Research Foundation(2022A1515010920)+1 种基金the Science and Technology Foundation of Shenzhen(JCYJ20190808153609561)the Open Research Found of Songshan Lake Materials Laboratory(2021SLABFN04)。
文摘Benefiting from the advantageous features of structural diversity and resource renewability,organic electroactive compounds are considered as attractive cathode materials for aqueous Zn-ion batteries(ZIBs).In this review,we discuss the recent developments of organic electrode materials for aqueous ZIBs.Although the proton(H^(+))storage chemistry in aqueous Zn-organic batteries has triggered an overwhelming literature surge in recent years,this topic remains controversial.Therefore,our review focuses on this significant issue and summarizes the reported electrochemical mechanisms,including pure Zn^(2+)intercalation,pure H^(+)storage,and H^(+)/Zn^(2+)co-storage.Moreover,the impact of H^(+)storage on the electrochemical performance of aqueous ZIBs is discussed systematically.Given the significance of H^(+)storage,we also highlight the relevant characterization methods employed.Finally,perspectives and directions on further understanding the charge storage mechanisms of organic materials are outlined.We hope that this review will stimulate more attention on the H^(+)storage chemistry of organic electrode materials to advance our understanding and further its application.
基金We acknowledge the financial support from the Open Research Fund of Songshan Lake Materials Laboratory(No.2021SLABFN04)the National Natural Science Foundation of China(Nos.22005207 and U20A20249)the Regional Innovation and Development Joint Fund,and the Science and Technology Program of Guangdong Province of China(No.2022A0505030028).
文摘Electrolytes hold the key to realizing reliable zinc(Zn)anodes.Divergent organic molecules have been proven effective in stabilizing Zn anodes;however,irrational comparisons exist due to the uncontrolled molecular weights and functional group amounts.In this work,two“isomeric molecules”:1,2-dimethoxyethane(DME)and 1-methoxy-2-propanol(PM),with identical molecular weights but different functional groups,have been studied as co-solvents in electrolytes,which have delivered distinct electrochemical performance.Experimental and simulative study indicates the dipole moment induced by the hydroxyl groups in PM(higher molecular polarity than ether groups in DME)reconstructs the space charge region,enhances the concentration of Zn^(2+)in the vicinity of Zn anodes,and in-situ derives different solid electrolyte interphase(SEI)models and electrode-electrolyte interfaces,resulting in exceptional cycling stability.Remarkably,the Zn||Cu cell with PM worked over 2000 cycles with high Coulombic efficiency(CE)of 99.7%.The Zn||Zn symmetric cell cycled over 2000 h at 1 mA·cm^(−2),and showed excellent stability at an ultrahigh current density of 10 mA·cm^(−2)and capacity of 20 mAh·cm^(−2)over 200 h(depth of discharge,DOD of 70%).The Zn||sodium vanadate pouch cell with a high mass loading of 6.3 mg·cm^(−2)and a high capacity of 24 mAh demonstrates superior cyclability after 570 h.This work can be a good starting point to provide reliable guidance on electrolyte design for practical aqueous Zn batteries.
基金the Guangdong Basic and Applied Basic Research Foundation(grant number:2019A1515011819,2021B1515120004)National Natural Science Foundation of China(22005207)Open Research Fund of Songshan Lake Materials Laboratory(2021SLABFN04).
文摘Non-flow aqueous zinc-bromine batteries without auxiliary components(e.g.,pumps,pipes,storage tanks)and ion-selective membranes represent a cost-effective and promising technology for large-scale energy storage.Unfortunately,they generally suffer from serious diffusion and shuttle of polybromide(Br^(-),Br^(3-))due to the weak physical adsorption between soluble polybromide and host carbon materials,which results in low energy efficiency and poor cycling stability.Here,we develop a novel self-capture organic bromine material(1,10-bis[3-(trimethylammonio)propyl]-4,40-bipyridinium bromine,NVBr4)to successfully realize reversible solid complexation of bromide components for stable non-flow zinc-bromine battery applications.The quaternary ammonium groups(NV^(4+)ions)can effectively capture the soluble polybromide species based on strong chemical interaction and realize reversible solid complexation confined within the porous electrodes,which transforms the conventional“liquid-liquid”conversion of soluble bromide components into“liquid-solid”model and effectively suppresses the shuttle effect.Thereby,the developed non-flow zinc-bromide battery provides an outstanding voltage platform at 1.7 V with a notable specific capacity of 325 mAh g^(-1)NVBr4(1 A g^(-1)),excellent rate capability(200 mAh g^(-1)NVBr4 at 20 A g^(-1)),outstanding energy density of 469.6 Wh kg^(-1)and super-stable cycle life(20,000 cycles with 100%Coulombic efficiency),which outperforms most of reported zinc-halogen batteries.Further mechanism analysis and DFT calculations demonstrate that the chemical interaction of quaternary ammonium groups and bromide species is the main reason for suppressing the shuttle effect.The developed strategy can be extended to other halogen batteries to obtain stable charge storage.
