The ripple effect induced by uncontrollable Zn deposition is considered as the Achilles heel for developing high-performance aqueous Zn-ion batteries.For this problem,this work reports a design concept of 3D artificia...The ripple effect induced by uncontrollable Zn deposition is considered as the Achilles heel for developing high-performance aqueous Zn-ion batteries.For this problem,this work reports a design concept of 3D artificial array interface engineering to achieve volume stress elimination,preferred orientation growth and dendrite-free stable Zn metal anode.The mechanism of MXene array interface on modulating the growth kinetics and deposition behavior of Zn atoms were firstly disclosed on the multi-scale level,including the in-situ optical microscopy and transient simulation at the mesoscopic scale,in-situ Raman spectroscopy and in-situ X-ray diffraction at the microscopic scale,as well as density functional theory calculation at the atomic scale.As indicated by the electrochemical performance tests,such engineered electrode exhibits the comprehensive enhancements not only in the resistance of corrosion and hydrogen evolution,but also the rate capability and cyclic stability.High-rate performance(20 mA cm^(-2))and durable cycle lifespan(1350 h at 0.5 mA cm^(-2),1500 h at 1 mA cm^(-2)and 800 h at 5 mA cm^(-2))can be realized.Moreover,the improvement of rate capability(214.1 mAh g^(-1)obtained at 10 A g^(-1))and cyclic stability also can be demonstrated in the case of 3D MXene array@Zn/VO2battery.Beyond the previous 2D closed interface engineering,this research offers a unique 3D open array interface engineering to stabilize Zn metal anode,the controllable Zn deposition mechanism revealed is also expected to deepen the fundamental of rechargeable batteries including but not limited to aqueous Zn metal batteries.展开更多
Aqueous zinc ion batteries show prospects for next-generation renewable energy storage devices.However,the practical applications have been limited by the issues derived from Zn anode.As one of serious problems,Zn den...Aqueous zinc ion batteries show prospects for next-generation renewable energy storage devices.However,the practical applications have been limited by the issues derived from Zn anode.As one of serious problems,Zn dendrite growth caused from the uncontrollable Zn deposition is unfavorable.Herein,with the aim to regulate Zn deposition,an artificial solid–electrolyte interface is subtly engineered with a perovskite type material,BaTiO3,which can be polarized,and its polarization could be switched under the external electric field.Resulting from the aligned dipole in BaTiO3 layer,zinc ions could move in order during cycling process.Regulated Zn migration at the anode/electrolyte interface contributes to the even Zn stripping/plating and confined Zn dendrite growth.As a result,the reversible Zn plating/stripping processes for over 2000 h have been achieved at 1 mA cm^(−2) with capacity of 1 mAh cm−2.Furthermore,this anode endowing the electric dipoles shows enhanced cycling stability for aqueous Zn-MnO2 batteries.The battery can deliver nearly 100%Coulombic efficiency at 2 Ag^(−1) after 300 cycles.展开更多
The formation and growth of Li-dendrites caused by inhomogeneous Li deposition severely hinder the commercial applications of Li metal batteries due to the consequence of short-circuiting.Herein,we propose a Janus bil...The formation and growth of Li-dendrites caused by inhomogeneous Li deposition severely hinder the commercial applications of Li metal batteries due to the consequence of short-circuiting.Herein,we propose a Janus bilayer composed of black phosphorus(BP)and graphene oxide(GO)as an artificial interface with chemical/mechanical stability and well-regulated Li-ion flux distribution for Li metal anode protection.Owing to the synergy between the fast Li-ion transport of BP in the inner layer and the high mechanical and chemical stability of GO in the outer layer,the GO/BP with good electrolyte wettability acts as a Li-ion regulator that can induce homogeneous growth of Li to suppress the Li dendrites growth.Accordingly,long-term stability(500 h at 1 mA cm^(-2))with a low overpotential of 30 mV is achieved in the symmetric cell with GO/BP-Li anode.Furthermore,the Li–S cell with GO/BP-Li exhibits enhanced cycling performance with a high capacity retention rate of 76.2%over 500 cycles at 1 C.展开更多
To study the influence of construction interfaces on dynamic characteristics of roller compacted concrete dams(RCCDs),mechanical properties of construction interfaces are firstly analyzed. Then, the viscous-spring art...To study the influence of construction interfaces on dynamic characteristics of roller compacted concrete dams(RCCDs),mechanical properties of construction interfaces are firstly analyzed. Then, the viscous-spring artificial boundary(VSAB) is adopted to simulate the radiation damping of their infinite foundations, and based on the Marc software, a simplified seismic motion input method is presented by the equivalent nodal loads. Finally, based on the practical engineering of a RCC gravity dam, effects of radiation damping and construction interfaces on the dynamic characteristics of dams are investigated in detail. Analysis results show that dynamic response of the RCC gravity dam significantly reduces about 25% when the radiation damping of infinite foundation is considered. Hot interfaces and the normal cold interfaces have little influence on the dynamic response of the RCC gravity dam.However, nonlinear fracture along the cold interfaces at the dam heel will occur under the designed earthquake if the cold interfaces are combined poorly. Therefore, to avoid the fractures along the construction interfaces under the potential super earthquakes,combination quality of the RCC layers should be significantly ensured.展开更多
Lithium metal anode(LMA) is a promising candidate for achieving next-generation high-energy-density batteries due to its ultrahigh theoretical capacity and most negative electrochemical potential. However, the practic...Lithium metal anode(LMA) is a promising candidate for achieving next-generation high-energy-density batteries due to its ultrahigh theoretical capacity and most negative electrochemical potential. However, the practical application of lithium metal battery(LMB) is largely retarded by the instable interfaces, uncontrolled dendrites, and rapid capacity deterioration. Herein, we present a comprehensive overview towards the working principles and inherent challenges of LMAs. Firstly, we diligently summarize the intrinsic mechanism of Li stripping and plating process. The recent advances in atomic and mesoscale simulations which are crucial in guiding mechanism study and material design are also summarized. Furthermore, the advanced engineering strategies which have been proved effective in protecting LMAs are systematically reviewed, including electrolyte optimization, artificial interface, composite/alloy anodes and so on. Finally, we highlight the current limitations and promising research directions of LMAs. This review sheds new lights on deeply understanding the intrinsic mechanism of LMAs, and calls for more endeavors to realize practical Li metal batteries.展开更多
Rechargeable magnesium batteries(RMBs)have attracted tremendous attention in energy storage ap-plications in term of high abundance,high specific capacity and remarkable safety of metallic magne-sium(Mg)anode.However,...Rechargeable magnesium batteries(RMBs)have attracted tremendous attention in energy storage ap-plications in term of high abundance,high specific capacity and remarkable safety of metallic magne-sium(Mg)anode.However,a serious passivation of Mg anode in the conventional electrolytes leads to extremely poor plating/stripping performance,further hindering its applications.Herein,we propose a convenient method to construct an artificial interphase layer on Mg anode by substitution and alloy-ing reactions between SbCl_(3) and Mg.This Sb-based artificial interphase layer containing mainly MgCl_(2) and Mg_(3) Sb_(2) endows the significantly improved interfacial kinetics and electrochemical performance of Mg anode.The overpotential of Mg plating/stripping in conventional Mg(TFSI)2/DME electrolytes is vastly reduced from over 2 V to 0.25-0.3 V.Combining experiments and calculations,we demonstrate that un-der the uniform distribution of MgCl_(2) and Mg_(3) Sb_(2),an electric field with a favorable potential gradient is formed on the anode surface,which enables swift Mg^(2+)migration.Meanwhile,this layer can inhibit the decomposition of electrolytes to protect anode.This work provides an in-depth exploration of the artificial solid-electrolyte interface(SEI)construction,and a more achievable and safe path to realize the application of metallic Mg anode in RMBs.展开更多
Zn-air batteries are promising energy storage and conversion systems to replace the conventional lithiumbased ones.However,their applications have been greatly hindered by the formation of Zn dendrites and ZnO passiva...Zn-air batteries are promising energy storage and conversion systems to replace the conventional lithiumbased ones.However,their applications have been greatly hindered by the formation of Zn dendrites and ZnO passivation layer on the Zn anodes.Herein,we report the fabrication of an artificial protective layer comprised of N-doped threedimensional hollow porous multi-nanochannel carbon fiber with well-dispersed TiO_(2) nanoparticles(HMCNF).The incorporated TiO;nanoparticles and N dopants improve the ion flux distribution and promote the surface adsorption,facilitating the interfacial pseudocapacitive behaviors during Zn deposition.The hierarchical architecture also induces homogenous electric field distribution at the anode/electrolyte interface.Accordingly,the deposition behavior of Zn is regulated,giving rise to enhanced utilization and rechargeability of Zn.When integrated in alkaline Zn-air batteries,the HMCNF-coated Zn anodes exhibit improved electrochemical performances relative to those with the bare Zn anodes,demonstrating a versatile strategy to boost energy storage of metal anodes through optimizing surface adsorption properties.展开更多
Battery technology inspires a flexible,organic,nonvolatile device for neuromorphic circuits that needs only millivolts to change state.The researchers have created a new form of'artificial synapse'that may one...Battery technology inspires a flexible,organic,nonvolatile device for neuromorphic circuits that needs only millivolts to change state.The researchers have created a new form of'artificial synapse'that may one day be used to create flexible circuitry that could directly interface with the brain.展开更多
Potassium metal batteries(PMBs)have become a paramount alternative energy storage technology to lithium-ion batteries,due to their low cost and potential energy density.However,uncontrolled dendrite growth interferes ...Potassium metal batteries(PMBs)have become a paramount alternative energy storage technology to lithium-ion batteries,due to their low cost and potential energy density.However,uncontrolled dendrite growth interferes with the stability of the interfacial anode,leading to significant capacity degradation and safety hazards.Herein,a facile reactive prewetting strategy is proposed to discourage dendrite growth by constructing a functional KF/Znrich hybrid interface layer on K metal.The KF/Zn@K anode design functions like an interconnected paddy field,stabilizing the anode interface through the preferential redistribution of Kþflux/electrons,continuous transport paths,and enhanced transport dynamics.As anticipated,symmetrical batteries exhibit an extended cycling lifetime of over 2000 h,with reduced voltage hysteresis at 0.5 mA cm^(-2) and 0.5 mAh cm^(-2).Furthermore,when the KF/Zn@K anode is applied to full batteries coupled with PTCDA,a boosted reversible capacity of 61.6 mAh g1 at 5 C is present over 3000 cycles.This interfacial control creates rational possibilities for constructing highefficiency,stable K metal anodes.展开更多
The practical application of aqueous zinc-ion batteries(ZIBs)is limited by the growth of dendrite during cycling.How to rationally design and construct an efficient artificial interface layer by selecting suitable bui...The practical application of aqueous zinc-ion batteries(ZIBs)is limited by the growth of dendrite during cycling.How to rationally design and construct an efficient artificial interface layer by selecting suitable building units to control the dendrite growth is still a challenge.Herein,a porous boron nitride nanofibers(BNNFs)artificial interface layer was constructed,and its working mechanisms were revealed by both experiments(electrochemical characterization and in-situ optical microscope)and theoretical calculations(density functional theory(DFT)and finite element simulation).The insulated BNNFs layer leads to position-selected electroplating between BNNFs layer and Zn foil.The unique negatively charged surface and porosity of BNNFs contribute to the self-concentrating and pumping features of Zn ions,thus suppressing the concentration polarization on the Zn surface.Additionally,densely arranged porous BNNFs have a shunt effect on Zn ions diffusion,resulting in uniform distributions of Zn ions and electric field.The introduced BNNFs layer not only makes Zn deposition uniform but also restrains the dendrite growth,therefore the Zn+BNNFs symmetric cells perform ultralong stable cycling for 1,600 h at 1 mA·cm–2 and more than 500 h at 10 mA·cm–2.Moreover,Zn+BNNFs||CNT/MnO2 battery presents a high initial capacity of 293.6 mAh·g–1 and an excellent retention rate of 97.6%at 1 A·g–1 after 400 cycles,while Zn||CNT/MnO2 battery only maintains 37.1%discharge capacity.This artificial interface layer with negatively charged BNNFs exhibits excellent dendrite-inhibit and may have enormous prospects in other metal batteries.展开更多
The finite lithium-ion utilization,short cycling life,and lower capacity retention caused by irreversible dendrite growth become the maximum dilemma in lithium metal batteries’(LMBs’)commercialization.Herein,a perfl...The finite lithium-ion utilization,short cycling life,and lower capacity retention caused by irreversible dendrite growth become the maximum dilemma in lithium metal batteries’(LMBs’)commercialization.Herein,a perfluoroalkyl-functionalized covalent organic framework(COF-F6)equipped with high stability and supernal proton conduction is introduced as an artificial solid electrolyte interface to stable the lithium metal anode.Benefiting from the strong electron-withdrawing effect of perfluoroalkyl,Li^(+)will be freed more by the competition of electronegative fluorine(F)and bis(trifluoromethanesulphonyl)imide anion(TFSI^(-)).The dissociation of LiTFSI and process of Li^(+)desolvation are easier to achieve.In addition,high electronegative fluorine can also regulate local electron-cloud density to induce the fast immigration of Li^(+).All the above roles contribute to improving the Li^(+)transfer number(0.7)and achieving the goal of inhibiting Li dendrite.As a result,the perfluoroalkyl COF-F6 modified LMB presents outstanding cycling stability.The symmetric batteries accomplish an overlong life-span of more than 5000 h with a lower hysteresis voltage(11 mV)at 5 mA·cm^(-2).Also,no dendrites are observed when using an in-situ optical microscope to learn the process of Li deposition.Therefore,this dendrite-free protection tactic holds broad prospects for the practical application of Li metal anodes.展开更多
基金financially the National Natural Science Foundation of China(Nos.22178221,22208221)Shenzhen Science and Technology Program(Nos.JCYJ20200109105805902)+1 种基金Natural Science Foundation of Guangdong Province(Nos.2021A1515110751)China Postdoctoral Science Foundation(Nos.2021M702255)。
文摘The ripple effect induced by uncontrollable Zn deposition is considered as the Achilles heel for developing high-performance aqueous Zn-ion batteries.For this problem,this work reports a design concept of 3D artificial array interface engineering to achieve volume stress elimination,preferred orientation growth and dendrite-free stable Zn metal anode.The mechanism of MXene array interface on modulating the growth kinetics and deposition behavior of Zn atoms were firstly disclosed on the multi-scale level,including the in-situ optical microscopy and transient simulation at the mesoscopic scale,in-situ Raman spectroscopy and in-situ X-ray diffraction at the microscopic scale,as well as density functional theory calculation at the atomic scale.As indicated by the electrochemical performance tests,such engineered electrode exhibits the comprehensive enhancements not only in the resistance of corrosion and hydrogen evolution,but also the rate capability and cyclic stability.High-rate performance(20 mA cm^(-2))and durable cycle lifespan(1350 h at 0.5 mA cm^(-2),1500 h at 1 mA cm^(-2)and 800 h at 5 mA cm^(-2))can be realized.Moreover,the improvement of rate capability(214.1 mAh g^(-1)obtained at 10 A g^(-1))and cyclic stability also can be demonstrated in the case of 3D MXene array@Zn/VO2battery.Beyond the previous 2D closed interface engineering,this research offers a unique 3D open array interface engineering to stabilize Zn metal anode,the controllable Zn deposition mechanism revealed is also expected to deepen the fundamental of rechargeable batteries including but not limited to aqueous Zn metal batteries.
基金the partial financial support from the National Natural Science Foundation of China(21935003 and 21805182)National Key Research and Development Plan(2016YFB0901503)+1 种基金Shanghai Pujiang Program(18PJ1403800)the support from the Hundreds of Talents program of Sun Yat-sen University。
文摘Aqueous zinc ion batteries show prospects for next-generation renewable energy storage devices.However,the practical applications have been limited by the issues derived from Zn anode.As one of serious problems,Zn dendrite growth caused from the uncontrollable Zn deposition is unfavorable.Herein,with the aim to regulate Zn deposition,an artificial solid–electrolyte interface is subtly engineered with a perovskite type material,BaTiO3,which can be polarized,and its polarization could be switched under the external electric field.Resulting from the aligned dipole in BaTiO3 layer,zinc ions could move in order during cycling process.Regulated Zn migration at the anode/electrolyte interface contributes to the even Zn stripping/plating and confined Zn dendrite growth.As a result,the reversible Zn plating/stripping processes for over 2000 h have been achieved at 1 mA cm^(−2) with capacity of 1 mAh cm−2.Furthermore,this anode endowing the electric dipoles shows enhanced cycling stability for aqueous Zn-MnO2 batteries.The battery can deliver nearly 100%Coulombic efficiency at 2 Ag^(−1) after 300 cycles.
基金financially supported by the National Natural Science Foundation of China(21771154)the Shenzhen Fundamental Research Programs(JCYJ20190809161013453)+1 种基金the Fundamental Research Funds for the Central Universities(20720220031)the 111 Project(B16029)。
文摘The formation and growth of Li-dendrites caused by inhomogeneous Li deposition severely hinder the commercial applications of Li metal batteries due to the consequence of short-circuiting.Herein,we propose a Janus bilayer composed of black phosphorus(BP)and graphene oxide(GO)as an artificial interface with chemical/mechanical stability and well-regulated Li-ion flux distribution for Li metal anode protection.Owing to the synergy between the fast Li-ion transport of BP in the inner layer and the high mechanical and chemical stability of GO in the outer layer,the GO/BP with good electrolyte wettability acts as a Li-ion regulator that can induce homogeneous growth of Li to suppress the Li dendrites growth.Accordingly,long-term stability(500 h at 1 mA cm^(-2))with a low overpotential of 30 mV is achieved in the symmetric cell with GO/BP-Li anode.Furthermore,the Li–S cell with GO/BP-Li exhibits enhanced cycling performance with a high capacity retention rate of 76.2%over 500 cycles at 1 C.
基金Projects(20120094110005,20120094130003)supported by the Research Fund for the Doctoral Program of Higher Education of ChinaProjects(51379068,51139001,51279052,51209077,51179066)supported by the National Natural Science Foundation of China+1 种基金Project(NCET-11-0628)supported by the Program for New Century Excellent Talents in University,ChinaProjects(201201038,201101013)supported by the Public Welfare Industry Research Special Fund Project of Ministry of Water Resources of China
文摘To study the influence of construction interfaces on dynamic characteristics of roller compacted concrete dams(RCCDs),mechanical properties of construction interfaces are firstly analyzed. Then, the viscous-spring artificial boundary(VSAB) is adopted to simulate the radiation damping of their infinite foundations, and based on the Marc software, a simplified seismic motion input method is presented by the equivalent nodal loads. Finally, based on the practical engineering of a RCC gravity dam, effects of radiation damping and construction interfaces on the dynamic characteristics of dams are investigated in detail. Analysis results show that dynamic response of the RCC gravity dam significantly reduces about 25% when the radiation damping of infinite foundation is considered. Hot interfaces and the normal cold interfaces have little influence on the dynamic response of the RCC gravity dam.However, nonlinear fracture along the cold interfaces at the dam heel will occur under the designed earthquake if the cold interfaces are combined poorly. Therefore, to avoid the fractures along the construction interfaces under the potential super earthquakes,combination quality of the RCC layers should be significantly ensured.
基金supported by National Key Research and Development Program (2021YFB2400300)Beijing Natural Science Foundation (JQ20004)+1 种基金the National Natural Science Foundation of China (22109011, U1801257)Scientific and Technological Key Project of Shanxi Province (20191102003)。
文摘Lithium metal anode(LMA) is a promising candidate for achieving next-generation high-energy-density batteries due to its ultrahigh theoretical capacity and most negative electrochemical potential. However, the practical application of lithium metal battery(LMB) is largely retarded by the instable interfaces, uncontrolled dendrites, and rapid capacity deterioration. Herein, we present a comprehensive overview towards the working principles and inherent challenges of LMAs. Firstly, we diligently summarize the intrinsic mechanism of Li stripping and plating process. The recent advances in atomic and mesoscale simulations which are crucial in guiding mechanism study and material design are also summarized. Furthermore, the advanced engineering strategies which have been proved effective in protecting LMAs are systematically reviewed, including electrolyte optimization, artificial interface, composite/alloy anodes and so on. Finally, we highlight the current limitations and promising research directions of LMAs. This review sheds new lights on deeply understanding the intrinsic mechanism of LMAs, and calls for more endeavors to realize practical Li metal batteries.
基金financially supported by the Fundamental Re-search Funds for the Central Universities(No.2021CDJXDJH003)the Chongqing Technology Innovation and Application Devel-opment Project(No.CSTB2022TIAD-KPX0028).
文摘Rechargeable magnesium batteries(RMBs)have attracted tremendous attention in energy storage ap-plications in term of high abundance,high specific capacity and remarkable safety of metallic magne-sium(Mg)anode.However,a serious passivation of Mg anode in the conventional electrolytes leads to extremely poor plating/stripping performance,further hindering its applications.Herein,we propose a convenient method to construct an artificial interphase layer on Mg anode by substitution and alloy-ing reactions between SbCl_(3) and Mg.This Sb-based artificial interphase layer containing mainly MgCl_(2) and Mg_(3) Sb_(2) endows the significantly improved interfacial kinetics and electrochemical performance of Mg anode.The overpotential of Mg plating/stripping in conventional Mg(TFSI)2/DME electrolytes is vastly reduced from over 2 V to 0.25-0.3 V.Combining experiments and calculations,we demonstrate that un-der the uniform distribution of MgCl_(2) and Mg_(3) Sb_(2),an electric field with a favorable potential gradient is formed on the anode surface,which enables swift Mg^(2+)migration.Meanwhile,this layer can inhibit the decomposition of electrolytes to protect anode.This work provides an in-depth exploration of the artificial solid-electrolyte interface(SEI)construction,and a more achievable and safe path to realize the application of metallic Mg anode in RMBs.
基金supported by the National Natural Science Foundation of China(52002060)Shanghai Sailing Program(20YF1400600)the Fundamental Research Funds for the Central Universities(2232021D-06)。
文摘Zn-air batteries are promising energy storage and conversion systems to replace the conventional lithiumbased ones.However,their applications have been greatly hindered by the formation of Zn dendrites and ZnO passivation layer on the Zn anodes.Herein,we report the fabrication of an artificial protective layer comprised of N-doped threedimensional hollow porous multi-nanochannel carbon fiber with well-dispersed TiO_(2) nanoparticles(HMCNF).The incorporated TiO;nanoparticles and N dopants improve the ion flux distribution and promote the surface adsorption,facilitating the interfacial pseudocapacitive behaviors during Zn deposition.The hierarchical architecture also induces homogenous electric field distribution at the anode/electrolyte interface.Accordingly,the deposition behavior of Zn is regulated,giving rise to enhanced utilization and rechargeability of Zn.When integrated in alkaline Zn-air batteries,the HMCNF-coated Zn anodes exhibit improved electrochemical performances relative to those with the bare Zn anodes,demonstrating a versatile strategy to boost energy storage of metal anodes through optimizing surface adsorption properties.
文摘Battery technology inspires a flexible,organic,nonvolatile device for neuromorphic circuits that needs only millivolts to change state.The researchers have created a new form of'artificial synapse'that may one day be used to create flexible circuitry that could directly interface with the brain.
基金supported by the National Natural Science Foundation of China(Grant No.52272194)LiaoNing Revitalization Talents Program(Grant No.XLYC2007155).
文摘Potassium metal batteries(PMBs)have become a paramount alternative energy storage technology to lithium-ion batteries,due to their low cost and potential energy density.However,uncontrolled dendrite growth interferes with the stability of the interfacial anode,leading to significant capacity degradation and safety hazards.Herein,a facile reactive prewetting strategy is proposed to discourage dendrite growth by constructing a functional KF/Znrich hybrid interface layer on K metal.The KF/Zn@K anode design functions like an interconnected paddy field,stabilizing the anode interface through the preferential redistribution of Kþflux/electrons,continuous transport paths,and enhanced transport dynamics.As anticipated,symmetrical batteries exhibit an extended cycling lifetime of over 2000 h,with reduced voltage hysteresis at 0.5 mA cm^(-2) and 0.5 mAh cm^(-2).Furthermore,when the KF/Zn@K anode is applied to full batteries coupled with PTCDA,a boosted reversible capacity of 61.6 mAh g1 at 5 C is present over 3000 cycles.This interfacial control creates rational possibilities for constructing highefficiency,stable K metal anodes.
基金This work was financially supported by the National Natural Science Foundation of China(No.22075331)the National Thousand Youth Talents Project of the Chinese Government.
文摘The practical application of aqueous zinc-ion batteries(ZIBs)is limited by the growth of dendrite during cycling.How to rationally design and construct an efficient artificial interface layer by selecting suitable building units to control the dendrite growth is still a challenge.Herein,a porous boron nitride nanofibers(BNNFs)artificial interface layer was constructed,and its working mechanisms were revealed by both experiments(electrochemical characterization and in-situ optical microscope)and theoretical calculations(density functional theory(DFT)and finite element simulation).The insulated BNNFs layer leads to position-selected electroplating between BNNFs layer and Zn foil.The unique negatively charged surface and porosity of BNNFs contribute to the self-concentrating and pumping features of Zn ions,thus suppressing the concentration polarization on the Zn surface.Additionally,densely arranged porous BNNFs have a shunt effect on Zn ions diffusion,resulting in uniform distributions of Zn ions and electric field.The introduced BNNFs layer not only makes Zn deposition uniform but also restrains the dendrite growth,therefore the Zn+BNNFs symmetric cells perform ultralong stable cycling for 1,600 h at 1 mA·cm–2 and more than 500 h at 10 mA·cm–2.Moreover,Zn+BNNFs||CNT/MnO2 battery presents a high initial capacity of 293.6 mAh·g–1 and an excellent retention rate of 97.6%at 1 A·g–1 after 400 cycles,while Zn||CNT/MnO2 battery only maintains 37.1%discharge capacity.This artificial interface layer with negatively charged BNNFs exhibits excellent dendrite-inhibit and may have enormous prospects in other metal batteries.
基金The authors acknowledge financial supports provided by the National Natural Science Foundation of China(No.52064049)Key Laboratory of Solid-State Ions for Green Energy of Yunnan University(2019)+1 种基金Analysis and Measurements Center of Yunnan University for the sample testing service,the Electron Microscope Center of Yunnan University for the support of this workthe Postgraduate Research and Innovation Foundation of Yunnan University(No.KC-22221440)。
文摘The finite lithium-ion utilization,short cycling life,and lower capacity retention caused by irreversible dendrite growth become the maximum dilemma in lithium metal batteries’(LMBs’)commercialization.Herein,a perfluoroalkyl-functionalized covalent organic framework(COF-F6)equipped with high stability and supernal proton conduction is introduced as an artificial solid electrolyte interface to stable the lithium metal anode.Benefiting from the strong electron-withdrawing effect of perfluoroalkyl,Li^(+)will be freed more by the competition of electronegative fluorine(F)and bis(trifluoromethanesulphonyl)imide anion(TFSI^(-)).The dissociation of LiTFSI and process of Li^(+)desolvation are easier to achieve.In addition,high electronegative fluorine can also regulate local electron-cloud density to induce the fast immigration of Li^(+).All the above roles contribute to improving the Li^(+)transfer number(0.7)and achieving the goal of inhibiting Li dendrite.As a result,the perfluoroalkyl COF-F6 modified LMB presents outstanding cycling stability.The symmetric batteries accomplish an overlong life-span of more than 5000 h with a lower hysteresis voltage(11 mV)at 5 mA·cm^(-2).Also,no dendrites are observed when using an in-situ optical microscope to learn the process of Li deposition.Therefore,this dendrite-free protection tactic holds broad prospects for the practical application of Li metal anodes.