Humic acid(HA)was studied as a modifier in the SnO_(2) anode preparation for the electrochemical performance improvement.Scanning electron microscopy,180°peel test,and nanoindentation experiment were used to exam...Humic acid(HA)was studied as a modifier in the SnO_(2) anode preparation for the electrochemical performance improvement.Scanning electron microscopy,180°peel test,and nanoindentation experiment were used to examine the influence of the HA on electrode.The results showed that the addition of HA could improve the dispersion uniformity of all particles.The components were tightened,increasing the difficulty of peeling off the film from the current collector.The deformation resistance of the electrode was greatly enhanced by the HA modification.The electrochemical test results showed that the anode from the normal micron-sized SnO_(2)particles with the HA modifier exhibited significant progress in electrochemical performance compared with those without HA.The reversible specific capacity of the SnO_(2) anode can be maintained as high as 733.4 mA·h/g at a current density of 100 mA/g after 50 cycles.Therefore,HA is a promising modifier for anode preparation of lithium-ion batteries.展开更多
Anodic oxidation with different electrolyte was employed to improve the electrochemical properties of carbon paper as negative electrode for vanadium redox battery(VRB).The treated carbon paper exhibits enhanced elect...Anodic oxidation with different electrolyte was employed to improve the electrochemical properties of carbon paper as negative electrode for vanadium redox battery(VRB).The treated carbon paper exhibits enhanced electrochemical activity for V^2+/V^3+redox reaction.The sample(CP-NH3)treated in NH3 solution demonstrates superior performance in comparison with the sample(CP-NaOH)treated in NaOH solution.X-ray photoelectron spectroscopy results show that oxygen-and nitrogen-containing functional groups have been introduced on CP-NH3 surface by the treatment,and Raman spectra confirm the increased surface defect of CP-NH3.Energy storage performance of cell was evaluated by charge/discharge measurement by using CP-NH3.Usage of CP-NH3 can greatly improve the cell performance with energy efficiency increase of 4.8%at 60 mA/cm^2.The excellent performance of CP-NH3 mainly results from introduction of functional groups as active sites and improved wetting properties.This work reveals that anodic oxidation is a clean,simple,and efficient method for boosting the performance of carbon paper as negative electrode for VRB.展开更多
A new type of lead-based porous anode in zinc electrowinning was prepared by negative pressure infiltration. The anodic polarization potential and corrosion rate were studied and compared with those of traditional fia...A new type of lead-based porous anode in zinc electrowinning was prepared by negative pressure infiltration. The anodic polarization potential and corrosion rate were studied and compared with those of traditional fiat anodes (Pb-0.8%Ag) used in industry. The anode corrosion rate was determined by anode actual current density and microstructure. The results show that the anodic oxygen evolution potential decreases first and then increases with the decrease of pore diameter. The anodic potential decreases to the lowest value of 1.729 V at the pore diameter of 1.25-1.60 mm. The porous anode can decrease its actual current density and thus decrease the anodic corrosion rate. When the pore diameter is 1.60-2.00 mm, the anodic relative corrosion rate reaches the lowest value of 52.1%.展开更多
An investigation was performed on the suitability of carbon materials, metallic lead and its alloys as substrates for zinc negative electrode in acid PbO2-Zn single flow batteries. The zinc deposition process was carr...An investigation was performed on the suitability of carbon materials, metallic lead and its alloys as substrates for zinc negative electrode in acid PbO2-Zn single flow batteries. The zinc deposition process was carried out in the mediumofl mol.L 1H2SO4 at room temperature. No maximum current appears on the potentiostatic current transients for the zinc deposition on lead and its alloys. With increasing overpotential, the progressive nucleation turns to be a 3D-instantaneous nucleation process for the resin-graphite composite. Hydrogen evolution on the graphite composite is effectively suppressed with the doping of a polymer resin. The hydrogen evolution reaction on the lead is relatively weak, while on the lead alloys, it becomes serious to a certain degree. Although the ex- change current density of zinc deposition and dissolution process on the graphite composite is relatively low, the zinc corrosion is weakened to a great extent. With the increase of deposition time, zinc deposits are more compact. The cyclings of zinc galvanostatic charge-discharge on the graphite composite provide more than 90% of coulombic and 80% of energy efficiencies, and exhibit superior cycling stability during the first 10 cycles.展开更多
This paper presents a straightforward model studying the performance of a solid oxide electrolysis cell at less computational effort while is still comprehensive accounting for details of all physics involved. The mod...This paper presents a straightforward model studying the performance of a solid oxide electrolysis cell at less computational effort while is still comprehensive accounting for details of all physics involved. The model is one dimensional and can be used to optimize SOECs that have composite electrodes. It includes an average mass transfer analysis used to simulate concentration polarization, activation polarization, as well as ohmic loss. The electrochemical reaction that occurs within the electrode functional layers has been accounted for in the calculation of the concentration polarization. This is believed to give a more realistic view of the mass transfer that occurs in SOECs with composite electrodes via a simple and straightforward one dimensional model. Experimental work with SOECs also has been done and some results are reported. The simulation results are compared with experimental data and the agreement is satisfactory. The model can be conveniently used for optimization of the SOEC electrodes and operational conditions.展开更多
Integrating high content carbon into the negative electrodes of advanced lead–acid batteries effectively eliminates the sulfation and improves the cycle life,but brings the problem of hydrogen evolution,which increas...Integrating high content carbon into the negative electrodes of advanced lead–acid batteries effectively eliminates the sulfation and improves the cycle life,but brings the problem of hydrogen evolution,which increases inner pressure and accelerates the water loss.In this review,the mechanism of hydrogen evolution reaction in advanced lead–acid batteries,including lead–carbon battery and ultrabattery,is briefly reviewed.The strategies on suppression hydrogen evolution via structure modifications of carbon materials and adding hydrogen evolution inhibitors are summarized as well.The review points out effective ways to inhibit hydrogen evolution and prolong the cycling life of advanced lead–acid battery,especially in high-rate partial-state-of-charge applications.展开更多
Lithium (Li) metal is considered as the ultimate anode choice for developing next-generation high-energy batteries. However, the poor tolerance against moist air and the unstable solid electrolyte interphases (SEI) in...Lithium (Li) metal is considered as the ultimate anode choice for developing next-generation high-energy batteries. However, the poor tolerance against moist air and the unstable solid electrolyte interphases (SEI) induced by the intrinsic high reactivity of lithium bring series of obstacles such as the rigorous operating condition, the poor electrochemical performance, and safety anxiety of the cell, which to a large extent hinder the commercial utilization of Li metal anode. Here, an effective encapsulation strategy was reported via a facile drop-casting and a following heat-assisted cross-linking process. Benefiting from the inherent hydrophobicity and the compact micro-structure of the cross-linked poly(vinylidene-co-hex afluoropropylene) (PVDF–HFP), the as-encapsulated Li metal exhibited prominent stability toward moisture, as well corroborated by the evaluations both under the humid air at 25 °C with 30% relative humidity (RH) and pure water. Moreover, the encapsulated Li metal anode exhibits a decent electrochemical performance without substantially increasing the cell polarization due to the uniform and unblocked ion channels, which originally comes from the superior affinity of the PVDF–HFP polymer toward nonaqueous electrolyte. This work demonstrates a novel and valid encapsulation strategy for humiditysensitive alkali metal electrodes, aiming to pave the way for the large-scale and low-cost deployment of the alkali metal-based high-energy-density batteries.展开更多
To satisfy the requirements for various electric systems and energy storage devices with both high energy density and power density as well as long lifespan, sodium-ion capacitors(SICs) consisting of battery anode and...To satisfy the requirements for various electric systems and energy storage devices with both high energy density and power density as well as long lifespan, sodium-ion capacitors(SICs) consisting of battery anode and supercapacitor cathode, have attracted much attention due to the abundant resources and low cost of sodium source. SICs bridge the gap between the batteries and the supercapacitors,which can be used as competitive candidates for large-scale energy storage. In this review, the battery-type anode materials and the capacitor-type cathode materials are classified and introduced in detail. The advantages of various electrolytes including organic electrolytes, aqueous electrolytes and ion liquid electrolytes are also discussed sequentially. In addition, from the perspective of practical value, the presentations of the SICs at the current situation and the potential application in urban rail are displayed. Finally, the challenge,future research and prospects towards the SICs are put forward.展开更多
Tin-based nanomaterials have been extensively explored as high-capacity anode materials for lithium ion batteries(LIBs). However,the large volume changes upon repeated cycling always cause the pulverization of the e...Tin-based nanomaterials have been extensively explored as high-capacity anode materials for lithium ion batteries(LIBs). However,the large volume changes upon repeated cycling always cause the pulverization of the electrode materials. Herein,we report the fabrication of uniform SnS_2@C hollow microspheres from hydrothermally prepared SnO_2@C hollow microspheres by a solid-state sulfurization process. The as-prepared hollow SnS_2@C microspheres with unique carbon shell,as electrodes in LIBs,exhibit high reversible capacity of 814 mA h g^(-1) at a current density of 100 mA g^(-1),good cycling performance(783 mA h g^(-1) for 200 cycles maintained with an average degradation rate of 0.02% per cycle) and remarkable rate capability(reversible capabilities of 433 mA h g^(-1)at 2C). The hollow space could serve as extra space for volume expansion during the charge-discharge cycling,while the carbon shell can ensure the structural integrity of the microspheres. The preeminent electrochemical performances of the SnS_2@C electrodes demonstrate their promising application as anode materials in the next-generation LIBs.展开更多
With increasing demands for clean and sustainable energy, the advantages of high power density, high efficiency, and long life expectancy have made supercapacitors one of the major emerging devices for electrochemical...With increasing demands for clean and sustainable energy, the advantages of high power density, high efficiency, and long life expectancy have made supercapacitors one of the major emerging devices for electrochemical energy storage and power supply. However, one of the key challenges for SCs is their limited energy density, which has hindered their wider application in the field of energy storage. Despite significant progress has been achieved in the fabrication of high-energy density positive electrodes materials, negative electrode materials with high capacitance and a wide potential window are relatively less explored. In this review, we introduced some new negative electrode materials except for common carbon-based materials and what's more, based on our team's work recently, we put forward some new strategies to solve their inherent shortcoming as electrode material for SCs.展开更多
Aqueous zinc ion batteries(ZIBs)show great potential in large-scale energy storage systems for their advantages of high safety,low cost,high capacity,and environmental friendliness.However,the poor performance of Zn m...Aqueous zinc ion batteries(ZIBs)show great potential in large-scale energy storage systems for their advantages of high safety,low cost,high capacity,and environmental friendliness.However,the poor performance of Zn metal anode seriously hinders the application of ZIBs.Herein,we use the zinc-ion intercalatable V_(2)O_(5)nH_(2)O(VO)as the interface modification material,for the first time,to on-site build a Zn^(2+)-conductive ZnxV_(2)O_(5)nH_(2)O(ZnVO)interfacial layer via the spontaneous short-circuit reaction between the pre-fabricated VO film and Zn metal foil.Compared with the bare Zn,the ZnVO-coated Zn anode exhibits better electrochemical performances with dendrite-free Zn deposits,lower polarization,higher coulombic efficiency over 99%after long cycles and 10 times higher cycle life,which is confirmed by constructing Zn symmetrical cell and Zn|ZnSO_(4)+Li_(2)SO_(4)|LiFePO_(4) full cell.展开更多
Chemical prelithiation is regarded as a crucial method for improving the initial Coulombic efficiency(ICE)of Li-storage anodes.Herein,a substituent-engineered Li-cyanonaphthalene chemical prelithiation system is desig...Chemical prelithiation is regarded as a crucial method for improving the initial Coulombic efficiency(ICE)of Li-storage anodes.Herein,a substituent-engineered Li-cyanonaphthalene chemical prelithiation system is designed to simultaneously enhance the ICE and construct a multifunctional interfacial film for SiO electrodes.X-ray photoelectron spectroscopy(XPS),electron energy-loss spectroscopy(EELS),nuclear magnetic resonance(NMR)spectroscopy and atomic force microscopy(AFM)prove that the Licyanonaphthalene prelithiation reagent facilitates the formation of a rectified solid electrolyte interface(SEI)film in two ways:(1)generation of a gradient SEI film with an organic outer layer(dense Ncontaining organics,ROCO_(2)Li)and an inorganic LiF-enriched inner layer;(2)homogenization of the horizontal distribution of the composition,mechanical properties and surface potential.As a result,the prelithiated SiO electrode exhibits an ICE above 100%,enhanced CEs during cycling,better cycle stability and inhibition of lithium dendrite formation in the overcharged state.Notably,the prelithiated hard carbon/SiO(9:1)‖LHCoO_(2) cell displays an enhancement in the energy density of 62.3%.展开更多
Lithium(Li)metal is promising for high energy density batteries due to its low electrochemical redox potential and high specific capacity.However,the formation of dendrites and its tendency for large volume expansion ...Lithium(Li)metal is promising for high energy density batteries due to its low electrochemical redox potential and high specific capacity.However,the formation of dendrites and its tendency for large volume expansion during plating/stripping restrict the application of Li metal in practical scenarios.In this work,we developed reduced graphene oxide-graphitic carbon nitride(rGO-C3N4,GCN)with highly elastic and wrinkled structure as the current collector.Lithiophilic site C3N4 in GCN could reduce the nucleation overpotential.In addition,this material effectively inhibited electrode expansion during cycling.At the same time,due to its high elasticity,GCN could release the stress induced by Li deposition to maintain structural integrity of the electrode.Limetal anodes with GCN exhibited small volume expansion,high Coulombic efficiency(CE)of 98.6%within 300 cycles and long cycling life of more than 1700 h.This work described and demonstrated a new approach to construct flexible current collectors for stable lithium-metal anodes.展开更多
基金financially supported by the National Natural Science Foundation of China(Nos.U2004215,51974280,51774252)the Foundation of Henan Educational Committee,China(No.20HASTIT012).
文摘Humic acid(HA)was studied as a modifier in the SnO_(2) anode preparation for the electrochemical performance improvement.Scanning electron microscopy,180°peel test,and nanoindentation experiment were used to examine the influence of the HA on electrode.The results showed that the addition of HA could improve the dispersion uniformity of all particles.The components were tightened,increasing the difficulty of peeling off the film from the current collector.The deformation resistance of the electrode was greatly enhanced by the HA modification.The electrochemical test results showed that the anode from the normal micron-sized SnO_(2)particles with the HA modifier exhibited significant progress in electrochemical performance compared with those without HA.The reversible specific capacity of the SnO_(2) anode can be maintained as high as 733.4 mA·h/g at a current density of 100 mA/g after 50 cycles.Therefore,HA is a promising modifier for anode preparation of lithium-ion batteries.
基金Project(NCET-10-0946)supported by Program for New Century Excellent Talents in University of ChinaProject(2017JY0038)supported by Science and Technology Key Project of Sichuan Province,ChinaProject(2013TX8)supported by Titanium and Titanium Alloy Innovation Team of Panzhihua City,China
文摘Anodic oxidation with different electrolyte was employed to improve the electrochemical properties of carbon paper as negative electrode for vanadium redox battery(VRB).The treated carbon paper exhibits enhanced electrochemical activity for V^2+/V^3+redox reaction.The sample(CP-NH3)treated in NH3 solution demonstrates superior performance in comparison with the sample(CP-NaOH)treated in NaOH solution.X-ray photoelectron spectroscopy results show that oxygen-and nitrogen-containing functional groups have been introduced on CP-NH3 surface by the treatment,and Raman spectra confirm the increased surface defect of CP-NH3.Energy storage performance of cell was evaluated by charge/discharge measurement by using CP-NH3.Usage of CP-NH3 can greatly improve the cell performance with energy efficiency increase of 4.8%at 60 mA/cm^2.The excellent performance of CP-NH3 mainly results from introduction of functional groups as active sites and improved wetting properties.This work reveals that anodic oxidation is a clean,simple,and efficient method for boosting the performance of carbon paper as negative electrode for VRB.
基金Project(2007SK2009) supported by the Science and Technology Research Project of Hunan Province, China
文摘A new type of lead-based porous anode in zinc electrowinning was prepared by negative pressure infiltration. The anodic polarization potential and corrosion rate were studied and compared with those of traditional fiat anodes (Pb-0.8%Ag) used in industry. The anode corrosion rate was determined by anode actual current density and microstructure. The results show that the anodic oxygen evolution potential decreases first and then increases with the decrease of pore diameter. The anodic potential decreases to the lowest value of 1.729 V at the pore diameter of 1.25-1.60 mm. The porous anode can decrease its actual current density and thus decrease the anodic corrosion rate. When the pore diameter is 1.60-2.00 mm, the anodic relative corrosion rate reaches the lowest value of 52.1%.
基金Supported by the National Basic Research Program(973 Program)of China(2010CB227201)the State Key Program of National Natural Science of China(21236003)+2 种基金the National Natural Science Foundation of China(21476022)the Fundamental Research Funds for the Central Universities(JD1515 and YS1406)Beijing Higher Education Young Elite Teacher Project(YETP0509)
文摘An investigation was performed on the suitability of carbon materials, metallic lead and its alloys as substrates for zinc negative electrode in acid PbO2-Zn single flow batteries. The zinc deposition process was carried out in the mediumofl mol.L 1H2SO4 at room temperature. No maximum current appears on the potentiostatic current transients for the zinc deposition on lead and its alloys. With increasing overpotential, the progressive nucleation turns to be a 3D-instantaneous nucleation process for the resin-graphite composite. Hydrogen evolution on the graphite composite is effectively suppressed with the doping of a polymer resin. The hydrogen evolution reaction on the lead is relatively weak, while on the lead alloys, it becomes serious to a certain degree. Although the ex- change current density of zinc deposition and dissolution process on the graphite composite is relatively low, the zinc corrosion is weakened to a great extent. With the increase of deposition time, zinc deposits are more compact. The cyclings of zinc galvanostatic charge-discharge on the graphite composite provide more than 90% of coulombic and 80% of energy efficiencies, and exhibit superior cycling stability during the first 10 cycles.
文摘This paper presents a straightforward model studying the performance of a solid oxide electrolysis cell at less computational effort while is still comprehensive accounting for details of all physics involved. The model is one dimensional and can be used to optimize SOECs that have composite electrodes. It includes an average mass transfer analysis used to simulate concentration polarization, activation polarization, as well as ohmic loss. The electrochemical reaction that occurs within the electrode functional layers has been accounted for in the calculation of the concentration polarization. This is believed to give a more realistic view of the mass transfer that occurs in SOECs with composite electrodes via a simple and straightforward one dimensional model. Experimental work with SOECs also has been done and some results are reported. The simulation results are compared with experimental data and the agreement is satisfactory. The model can be conveniently used for optimization of the SOEC electrodes and operational conditions.
基金supported by the Science and Technology Program of State Grid Corporation of Chinathe National Thousand Talents Program of China
文摘Integrating high content carbon into the negative electrodes of advanced lead–acid batteries effectively eliminates the sulfation and improves the cycle life,but brings the problem of hydrogen evolution,which increases inner pressure and accelerates the water loss.In this review,the mechanism of hydrogen evolution reaction in advanced lead–acid batteries,including lead–carbon battery and ultrabattery,is briefly reviewed.The strategies on suppression hydrogen evolution via structure modifications of carbon materials and adding hydrogen evolution inhibitors are summarized as well.The review points out effective ways to inhibit hydrogen evolution and prolong the cycling life of advanced lead–acid battery,especially in high-rate partial-state-of-charge applications.
基金This work was supported by National Key Research and Development Program(2016YFA0202500)National Natural Science Foundation of China(21776019)Beijing Natural Science Foundation(L182021).
文摘Lithium (Li) metal is considered as the ultimate anode choice for developing next-generation high-energy batteries. However, the poor tolerance against moist air and the unstable solid electrolyte interphases (SEI) induced by the intrinsic high reactivity of lithium bring series of obstacles such as the rigorous operating condition, the poor electrochemical performance, and safety anxiety of the cell, which to a large extent hinder the commercial utilization of Li metal anode. Here, an effective encapsulation strategy was reported via a facile drop-casting and a following heat-assisted cross-linking process. Benefiting from the inherent hydrophobicity and the compact micro-structure of the cross-linked poly(vinylidene-co-hex afluoropropylene) (PVDF–HFP), the as-encapsulated Li metal exhibited prominent stability toward moisture, as well corroborated by the evaluations both under the humid air at 25 °C with 30% relative humidity (RH) and pure water. Moreover, the encapsulated Li metal anode exhibits a decent electrochemical performance without substantially increasing the cell polarization due to the uniform and unblocked ion channels, which originally comes from the superior affinity of the PVDF–HFP polymer toward nonaqueous electrolyte. This work demonstrates a novel and valid encapsulation strategy for humiditysensitive alkali metal electrodes, aiming to pave the way for the large-scale and low-cost deployment of the alkali metal-based high-energy-density batteries.
基金financially supported by the National Natural Science Foundation of China (51672308, 51972025 and 61888102)
文摘To satisfy the requirements for various electric systems and energy storage devices with both high energy density and power density as well as long lifespan, sodium-ion capacitors(SICs) consisting of battery anode and supercapacitor cathode, have attracted much attention due to the abundant resources and low cost of sodium source. SICs bridge the gap between the batteries and the supercapacitors,which can be used as competitive candidates for large-scale energy storage. In this review, the battery-type anode materials and the capacitor-type cathode materials are classified and introduced in detail. The advantages of various electrolytes including organic electrolytes, aqueous electrolytes and ion liquid electrolytes are also discussed sequentially. In addition, from the perspective of practical value, the presentations of the SICs at the current situation and the potential application in urban rail are displayed. Finally, the challenge,future research and prospects towards the SICs are put forward.
基金supported by the National Natural Science Foundation of China (51302323)the Program for New Century Excellent Talents in University (NCET-13-0594)the Innovationdriven Project of Central South University (2017CX001)
文摘Tin-based nanomaterials have been extensively explored as high-capacity anode materials for lithium ion batteries(LIBs). However,the large volume changes upon repeated cycling always cause the pulverization of the electrode materials. Herein,we report the fabrication of uniform SnS_2@C hollow microspheres from hydrothermally prepared SnO_2@C hollow microspheres by a solid-state sulfurization process. The as-prepared hollow SnS_2@C microspheres with unique carbon shell,as electrodes in LIBs,exhibit high reversible capacity of 814 mA h g^(-1) at a current density of 100 mA g^(-1),good cycling performance(783 mA h g^(-1) for 200 cycles maintained with an average degradation rate of 0.02% per cycle) and remarkable rate capability(reversible capabilities of 433 mA h g^(-1)at 2C). The hollow space could serve as extra space for volume expansion during the charge-discharge cycling,while the carbon shell can ensure the structural integrity of the microspheres. The preeminent electrochemical performances of the SnS_2@C electrodes demonstrate their promising application as anode materials in the next-generation LIBs.
基金supported by the National Natural Science Foundation of China(Grant Nos.51173212&21273290)the National Basic Research Program of China("973"Project)(Grant No.2015CB932304)+4 种基金the Natural Science Foundations of Guangdong Province(Grant Nos.S2013020012833&S2013030013474)Fundamental Research Fund for the Central Universities(Grant No.13lgpy51)SRF for ROCS,SEM(Grant No.[2012]1707)the Project of High Level Talents in Higher School of Guangdong Province,and Open-End Fund of Key Laboratory of Functional Inorganic Material Chemistry(Heilongjiang University)Ministry of Education,and the Research Fund for the Doctoral Program of Higher Education of China(Grant No.20120171110043)
文摘With increasing demands for clean and sustainable energy, the advantages of high power density, high efficiency, and long life expectancy have made supercapacitors one of the major emerging devices for electrochemical energy storage and power supply. However, one of the key challenges for SCs is their limited energy density, which has hindered their wider application in the field of energy storage. Despite significant progress has been achieved in the fabrication of high-energy density positive electrodes materials, negative electrode materials with high capacitance and a wide potential window are relatively less explored. In this review, we introduced some new negative electrode materials except for common carbon-based materials and what's more, based on our team's work recently, we put forward some new strategies to solve their inherent shortcoming as electrode material for SCs.
基金supported by the National Natural Science Foundation(51772115)the National Key Research and Development Program of China(2018YFE0206900)the Hubei Provincial Natural Science Foundation(2019CFA002)。
文摘Aqueous zinc ion batteries(ZIBs)show great potential in large-scale energy storage systems for their advantages of high safety,low cost,high capacity,and environmental friendliness.However,the poor performance of Zn metal anode seriously hinders the application of ZIBs.Herein,we use the zinc-ion intercalatable V_(2)O_(5)nH_(2)O(VO)as the interface modification material,for the first time,to on-site build a Zn^(2+)-conductive ZnxV_(2)O_(5)nH_(2)O(ZnVO)interfacial layer via the spontaneous short-circuit reaction between the pre-fabricated VO film and Zn metal foil.Compared with the bare Zn,the ZnVO-coated Zn anode exhibits better electrochemical performances with dendrite-free Zn deposits,lower polarization,higher coulombic efficiency over 99%after long cycles and 10 times higher cycle life,which is confirmed by constructing Zn symmetrical cell and Zn|ZnSO_(4)+Li_(2)SO_(4)|LiFePO_(4) full cell.
基金supported by the National Key Research and Development Program of China(2017YFA0206703)the National Natural Science Foundation of China(21701163,21671181,21831006,22075268)Ningbo Veken Battery Co.,Ltd.(2018B10043)。
文摘Chemical prelithiation is regarded as a crucial method for improving the initial Coulombic efficiency(ICE)of Li-storage anodes.Herein,a substituent-engineered Li-cyanonaphthalene chemical prelithiation system is designed to simultaneously enhance the ICE and construct a multifunctional interfacial film for SiO electrodes.X-ray photoelectron spectroscopy(XPS),electron energy-loss spectroscopy(EELS),nuclear magnetic resonance(NMR)spectroscopy and atomic force microscopy(AFM)prove that the Licyanonaphthalene prelithiation reagent facilitates the formation of a rectified solid electrolyte interface(SEI)film in two ways:(1)generation of a gradient SEI film with an organic outer layer(dense Ncontaining organics,ROCO_(2)Li)and an inorganic LiF-enriched inner layer;(2)homogenization of the horizontal distribution of the composition,mechanical properties and surface potential.As a result,the prelithiated SiO electrode exhibits an ICE above 100%,enhanced CEs during cycling,better cycle stability and inhibition of lithium dendrite formation in the overcharged state.Notably,the prelithiated hard carbon/SiO(9:1)‖LHCoO_(2) cell displays an enhancement in the energy density of 62.3%.
基金the National Natural Science Foundation of China(51525206 and 51927803)the National Key R&D Program of China(2016YFA0200100 and 2016YFB0100100)+2 种基金the Strategic Priority Research Program of the Chinese Academy of Sciences(XDA22010602)Liaoning Revitalization Talents Program(XLYC1908015)China Petrochemical Cooperation(218025)。
文摘Lithium(Li)metal is promising for high energy density batteries due to its low electrochemical redox potential and high specific capacity.However,the formation of dendrites and its tendency for large volume expansion during plating/stripping restrict the application of Li metal in practical scenarios.In this work,we developed reduced graphene oxide-graphitic carbon nitride(rGO-C3N4,GCN)with highly elastic and wrinkled structure as the current collector.Lithiophilic site C3N4 in GCN could reduce the nucleation overpotential.In addition,this material effectively inhibited electrode expansion during cycling.At the same time,due to its high elasticity,GCN could release the stress induced by Li deposition to maintain structural integrity of the electrode.Limetal anodes with GCN exhibited small volume expansion,high Coulombic efficiency(CE)of 98.6%within 300 cycles and long cycling life of more than 1700 h.This work described and demonstrated a new approach to construct flexible current collectors for stable lithium-metal anodes.