A spiro-type quaternary ammonium salt, spiro-(1,1′)-bipyrrolidinium tetrafluoroborate(SBP-BF4) was successfully prepared by an economical and efficient three-step process comprising the cyclization reaction of 1,4-di...A spiro-type quaternary ammonium salt, spiro-(1,1′)-bipyrrolidinium tetrafluoroborate(SBP-BF4) was successfully prepared by an economical and efficient three-step process comprising the cyclization reaction of 1,4-dibromobutane and pyrrolidine, and subsequent ion exchange pathway with KOH followed by neutralization reaction via HBF4 in the system of ethanol solution. 1H NMR, 13 C NMR, FI-IR and XPS analyses showed the structure of SBP-BF4. The as-obtained SBP-BF4 was dissolved in AN and used as the electrolyte for supercapacitor. Electrochemical measurements demonstrate that, compared with commercial electrolyte TEMA-BF4/AN, SBP-BF4/AN exhibits high ionic conductivity, lower resistance and improved cycling performance, which is due to its smaller ion size and stable symmetry structure.展开更多
Rapid fouling tests were used to investigate the scale-preventing property of ZX type scale inhibitors in evaporation of salt electrolyte. ZX type scale inhibitors were tested at high temperature under the boiling con...Rapid fouling tests were used to investigate the scale-preventing property of ZX type scale inhibitors in evaporation of salt electrolyte. ZX type scale inhibitors were tested at high temperature under the boiling conditions. The results indicate that ZX type scale inhibitors have remarkable scale preventing performance during evaporation of salt electrolyte even at the temperature up to 150℃. Among them, ZX Ⅲ type scale inhibitor is the best with the rate of scale-preventing reaching to 88.9%. In addition, the scale preventing mechanism of ZX type scale inhibitors was analyzed and its application prospect in the field of continuous commercial fouling preventing discussed.展开更多
Rare earth molten salt electrolytic slag(RMES)has emerged as a promising secondary resource for rare earth elements(REEs).This study introduces an innovative leaching technique for extracting REEs from RMES under atmo...Rare earth molten salt electrolytic slag(RMES)has emerged as a promising secondary resource for rare earth elements(REEs).This study introduces an innovative leaching technique for extracting REEs from RMES under atmospheric conditions,employing an alkali phase reconstruction method followed by an acid leaching process.Additionally,the external electric field was employed to enhance the reaction.Under the optimal reaction conditions:NaOH initial concentration of 70 wt%,NaOH-slag mass ratio of 4:1,temperature of 160℃,current density of 1000 A/m^(2),reaction time of 90 min,stirring speed of 300 r/min,HCl concentration of 4 mol/L,liquid-solid ratio of 15:1,and leaching time of 20 min,the leaching efficiencies of Nd and Pr reach up to 99.21%and 99.14%,respectively.Phase analysis indicates that the rare earth fluorides transform into rare earth hydroxides,significantly enhancing their solubility in acid solution.The imposition of an external electric field leads to pronounced disruption of the RMES surface,thereby promoting the formation of stable reactive oxygen species in the alkaline medium.This facilitates the decomposition of fluorinated rare earths and hastens the phase reconstruction,resulting in an enhanced leaching process.The achieved leaching efficiency with an external electric field is 37%higher than that without an electric field.展开更多
A new process was proposed to extract rare earth elements(REEs),Li and F from electrolytic slag of rare earth molten salt by synergistic roasting and acid leaching.Firstly,the thermodynamic analysis of roasting reacti...A new process was proposed to extract rare earth elements(REEs),Li and F from electrolytic slag of rare earth molten salt by synergistic roasting and acid leaching.Firstly,the thermodynamic analysis of roasting reaction was carried out,then the effects of roasting factors on leaching REEs,Li and F in slag were investigated.In additions,the mineral phase and morphology of molten salt slag,roasting slag and acid leaching slag were characterized,and the migration mechanism of REES,Li and F minerals in roasting and leaching process was analyzed.The results show that the synergistic roasting and activation of molten salt slag by CaO and Al_(2)(SO_(4))_(3)are thermodynamically feasible.The optimum roasting conditions are as follows:molten salt slag of 20 g,Al_(2)(SO_(4))_(3)of 31.25 g and CaO of 6.25 g,roasting temperature of 1173.15 K and reaction time of 2 h,under this condition,the leaching rates of Nd,Pr,Gd,Li and F are 92.47%,91.56%,91.08%,96.69%and 96.8%,respectively.X-ray powder diffraction(XRD)and scanning electron microscopy-energy dispersive X-ray spectroscopy(SEM-EDS)analysis show that the rare earth fluoride(REF3)in molten salt slag transforms into soluble rare earth oxide(REO)after roasting and activation.After leaching,the leaching residue is mainly strip CaSO4,indicating that REES,Li and F can be fully extracted from molten salt slag.展开更多
Due to the unique physical and chemical properties,rare earth elements(REEs)play a significant role in the high-tech field.In the past few decades,the rare earth reserve in China has been gradually decreasing and more...Due to the unique physical and chemical properties,rare earth elements(REEs)play a significant role in the high-tech field.In the past few decades,the rare earth reserve in China has been gradually decreasing and more pressure has been exerted on the global rare earth supply for the increasing demand of REEs,which indicates that it is essential to recycle secondary resources to meet the rare earth demand.As for rare earth molten salt electrolytic slag(REMES),although its high rare earth content has potential huge economic value,its high fluorine content of approximately 10 wt%-20 wt%can pollute the environment.Three methods are used to treat REMES.Hydro metallurgical and pyro-hydrometallurgical methods have gotten a big success for solving most of the hydrometallurgical problems,while some problems,like long route and waste water,need to be solved.Vacuum distillation is a new and promising method with a short process due to its harmlessness and high efficiency,but has shortcomings such as high energy consumption and material adaptability.This review presents these above three treatment methods,and the challenges and chances of using the recovery technique of REMES in an environmentally friendly way.展开更多
Developing supercapacitors(SCs)with long cycling life and wide operative voltage window is a significant topic in the field of aqueous electrolytes.Although the design of water in salt(WIS)electrolytes has pushed the ...Developing supercapacitors(SCs)with long cycling life and wide operative voltage window is a significant topic in the field of aqueous electrolytes.Although the design of water in salt(WIS)electrolytes has pushed the development of aqueous electrolytes to a new height,the WIS electrolytes with an operative voltage window of up to 2.5 V is still very scarce.Herein,in order to enrich the type of aqueous electrolyte with high operative voltage,tetramethylammonium trifluoromethanesulfonate(TMAOTf)based WIS electrolyte was used as a model to construct WIS based hybrid electrolyte with acetonitrile(ACN)co-solvent and LiTFSI co-solute.In view of the coordination effect of ACN and Lit on free water in TMAOTf based WIS electrolyte,the TMAt-Lit-AWIS electrolyte has the electrochemical stabilization window of up to 3.35 V.Further coupled with the commercial YP-50F electrodes,TMAt-Lit-AWIS based SCs exhibited wide operative voltage window(2.5 V),long cycling life(45,000 cycles)and good low-temperature performance(99.99%capacitance retention after 2000 cycles at20℃).The design of this hybrid electrolyte will enrich the types of aqueous hybrid electrolytes with long cycling life and wide operative voltage window.展开更多
Micro-sized silicon(mSi)anodes offer high capacity for next-generation lithium-ion batteries but suffer from severe volume changes,causing unstable interphases and poor cycling.Traditional electrolytes derive unstable...Micro-sized silicon(mSi)anodes offer high capacity for next-generation lithium-ion batteries but suffer from severe volume changes,causing unstable interphases and poor cycling.Traditional electrolytes derive unstable electrolyte/electrolyte interphases,and flammable solvents pose safety risks.Here,we introduce a non-flammable molten salt electrolyte,which consists of lithium bis(fluorosulfonyl)imide,potassium bis(fluorosulfonyl)amide,and cesium bis(fluorosulfonyl)imide in a mole ratio of 0.3:0.35:0.35(noted as Li_(0.3)K_(0.35)Cs_(0.35)FSA),that forms an inorganic interphase on mSi,stabilizing the electrode/electrolyte interface.Computational and experimental insights elucidate the FSA-anion decomposition-derived SEI predominantly of LiF,Li_(3)N,Li_(2)O,and Li_(2)S,which exhibits mechanical resilience and low interfacial resistance,effectively accommodating the significant volume expansion of silicon during lithiation/delithiation.As a result,the Li||mSi half-cell achieves 60.7%capacity retention after 100 cycles with 99.5%average Coulombic efficiency.Overall,the Li_(0.3)K_(0.35)Cs_(0.35)FSA electrolyte eliminates flammability concerns while enabling robust cycling performance.This work demonstrates a safe,high-energy battery system by coupling mSi anodes with stable molten salt electrolytes,addressing both interfacial instability and safety challenges in mSi-based lithium-ion batteries.展开更多
Supercapacitors,also known as electrical double-layer capacitors(EDLCs),store and release electrical charge through the adsorption and desorption of ions on the surface of highly porous carbon materials[1].To meet the...Supercapacitors,also known as electrical double-layer capacitors(EDLCs),store and release electrical charge through the adsorption and desorption of ions on the surface of highly porous carbon materials[1].To meet the increasing demands from electric vehicles,rail traffic,military and space applications,EDLCs are usually required to operate within a broad temperature range(subzero to 60°C or more)[2].展开更多
Biocompatible devices are widely employed in modernized lives and medical fields in the forms of wearable and implantable devices,raising higher requirements on the battery biocompatibility,high safety,low cost,and ex...Biocompatible devices are widely employed in modernized lives and medical fields in the forms of wearable and implantable devices,raising higher requirements on the battery biocompatibility,high safety,low cost,and excellent electrochemical performance,which become the evaluation criteria toward developing feasible biocompatible batteries.Herein,through conducting the battery implantation tests and leakage scene simulations on New Zealand rabbits,zinc sulfate electrolyte is proved to exhibit higher biosecurity and turns out to be one of the ideal zinc salts for biocompatible zinc-ion batteries(ZIBs).Furthermore,in order to mitigate the notorious dendrite growth and hydrogen evolution in mildly acidic electrolyte as well as improve their operating stability,Sn hetero nucleus is introduced to stabilize the zinc anode,which not only facilitates the planar zinc deposition,but also contributes to higher hydrogen evolution overpotential.Finally,a long lifetime of 1500 h for the symmetrical cell,the specific capacity of 150 mAh g^(-1)under 0.5 A g^(-1)for the Zn-MnO_(2)battery and 212 mAh g^(-1)under 5 A g^(-1)for the Zn—NH4V4O10 battery are obtained.This work may provide unique perspectives on biocompatible ZIBs toward the biosecurity of their cell components.展开更多
NiCl_(2) with high theoretical voltage and thermal decomposition temperature attracts much attention as cathode material for thermal batteries with the requirement of high power density, high energy density and long w...NiCl_(2) with high theoretical voltage and thermal decomposition temperature attracts much attention as cathode material for thermal batteries with the requirement of high power density, high energy density and long work time. Unfortunately, the practical utilization of thermal batteries with NiCl_(2) cathode is limited by their poor electrochemical performance under large current, even with the conventional Li F-Li Cl-Li Br all-lithium molten salt electrolyte which proposes ultrahigh lithium ion conductivity. In this work, an unexpected ionic exchange reaction between NiCl_(2) and Li Br in Li F-Li Cl-Li Br was found, which would be the main reason for the poor electrochemical behavior of thermal batteries with NiCl_(2) cathode and Li F-Li Cl-Li Br molten salt. On this basis, Li F-Li Cl-Li_(2)SO_(4), another all-lithium molten salt free of Li Br, was investigated as the new electrolyte for NiCl_(2) cathode. For the single cell of Li(Si)/Li F-Li Cl-Li_(2)SO_(4)/NiCl_(2), a discharge capacity of 377 mA h g^(-1)(with a cut-off voltage of 1.2 V) was achieved with large current density(500 mA cm^(-2)) applied at 520℃, which is almost twice of that of Li(Si)/Li F-Li Cl-Li Br/NiCl_(2)(190 mA h g^(-1)) at the same conditions.展开更多
The Ca-Pb electrode couple is considered to be one of the least expensive(~36$/(k W·h))among various optional materials for liquid-metal batteries(LMBs).The electrochemical properties of Ca-Pb alloy in a Ca|Li Cl...The Ca-Pb electrode couple is considered to be one of the least expensive(~36$/(k W·h))among various optional materials for liquid-metal batteries(LMBs).The electrochemical properties of Ca-Pb alloy in a Ca|Li Cl-Na Cl-Ca Cl_(2)|Pb cell were investigated in this paper.The electrode potential maintained a linear relationship in the current density range of 50-200 m A·cm^-2,which indicates that the alloying and dealloying processes of Ca with Pb attained rapid charge transfer and mass transport in the interface between the liquid electrode and electrolyte.The Ca-Pb electrode exhibited remarkable properties with a high discharge voltage of 0.6 V,a small self-discharge current density(<2 m A·cm^-2 at 600℃),and a high coulombic efficiency(>98.84%).The postmortem analysis showed that intermetallics Ca Pb3 and Ca Pb were uniformly distributed in the electrode with different molar fractions of Ca,which indicates that the nucleation of solid intermetallics did not hinder the diffusion of Ca in the electrode.This investigation on Ca-Pb electrode sheds light on the further research and the design of electrodes for Ca-based LMBs.展开更多
The reduction of Ni(Ⅱ) is an irreversible reaction and La(Ⅲ) cannot be reduced to La directly but be co-deposited inductively in the present of Ni(Ⅱ) in the Acetamide-Urea-NaBr molten salt electrolyte at 353 K. The...The reduction of Ni(Ⅱ) is an irreversible reaction and La(Ⅲ) cannot be reduced to La directly but be co-deposited inductively in the present of Ni(Ⅱ) in the Acetamide-Urea-NaBr molten salt electrolyte at 353 K. The uncrystallized alloy film of La-Ni is obtained by potentiostatic electrolysis, and the amount of La grows with increasing cathodic overpotential, molar ratios of La(Ⅲ) to Ni(Ⅱ) and the electrolysis time. The maximum amount of La in alloy film reaches to 78.81% (mass fraction) in present study.展开更多
The cycling performance, impedance variation, and cathode surface evolution of the Li/LiCoO2 cell using Li FSI–KFSI molten salt electrolyte are reported. It is found that this battery shows poor cycling performance, ...The cycling performance, impedance variation, and cathode surface evolution of the Li/LiCoO2 cell using Li FSI–KFSI molten salt electrolyte are reported. It is found that this battery shows poor cycling performance, with capacity retention of only about 67% after 20 cycles. It is essential to understand the origin of the instability. It is noticed that the polarization voltage and the impedance of the cell both increase slowly upon cycling. The structure and the properties of the pristine and the cycled LiCoO2 cathodes are investigated by x-ray diffraction（XRD）, scanning electron microscopy（SEM）, Raman spectroscopy, x-ray photoelectron spectroscopy（XPS）, and transmission electron microscopy（TEM）. It is found that the LiCoO2 particles are corroded by this molten salt electrolyte, and the decomposition by-product covers the surface of the LiCoO2 cathode after 20 cycles. Therefore, the surface side reaction explains the instability of the molten salt electrolyte with LiCoO2.展开更多
Crystallized lithium fluoride(LiF)melts at 848℃ upon heating,and evaporates subsequently at a remarkably high temperature of 1673℃,characterizing its excellent thermally stability as one of the most representative m...Crystallized lithium fluoride(LiF)melts at 848℃ upon heating,and evaporates subsequently at a remarkably high temperature of 1673℃,characterizing its excellent thermally stability as one of the most representative metal halides.The marriage between Li F and rechargeable batteries dates back to early activities related to the electrochemical properties of lithium metal(Li°)negative electrodes,in which the nonaqueous electrolytes containing fluorinated salts were generally employed,e.g.,lithium tetrafluoroborate(LiBF_(4)),lithium hexafluoroarsenate(LiAsF_(6)),lithium trifluoromethanesulfonate(CF_(3)SO_(3)Li)[1].展开更多
基金Project(51371198)supported by the National Natural Science Foundation of China
文摘A spiro-type quaternary ammonium salt, spiro-(1,1′)-bipyrrolidinium tetrafluoroborate(SBP-BF4) was successfully prepared by an economical and efficient three-step process comprising the cyclization reaction of 1,4-dibromobutane and pyrrolidine, and subsequent ion exchange pathway with KOH followed by neutralization reaction via HBF4 in the system of ethanol solution. 1H NMR, 13 C NMR, FI-IR and XPS analyses showed the structure of SBP-BF4. The as-obtained SBP-BF4 was dissolved in AN and used as the electrolyte for supercapacitor. Electrochemical measurements demonstrate that, compared with commercial electrolyte TEMA-BF4/AN, SBP-BF4/AN exhibits high ionic conductivity, lower resistance and improved cycling performance, which is due to its smaller ion size and stable symmetry structure.
基金the National Natural Science Foundation of China (No.59504005).
文摘Rapid fouling tests were used to investigate the scale-preventing property of ZX type scale inhibitors in evaporation of salt electrolyte. ZX type scale inhibitors were tested at high temperature under the boiling conditions. The results indicate that ZX type scale inhibitors have remarkable scale preventing performance during evaporation of salt electrolyte even at the temperature up to 150℃. Among them, ZX Ⅲ type scale inhibitor is the best with the rate of scale-preventing reaching to 88.9%. In addition, the scale preventing mechanism of ZX type scale inhibitors was analyzed and its application prospect in the field of continuous commercial fouling preventing discussed.
基金supported by the Natural Science Foundation of the Jiangxi Province(20224BAB204038)the Young Elite Scientists Sponsorship Program by CAST(2022QNRC001)+2 种基金the Ganzhou City Science and Technology Innovation Talent Project(2023CYZ26999)Jiangxi Provincial Key Laboratory of LowCarbon Processing and Utilization of Strategic Metal Mineral Resources(2023SSY01041)the Jiangxi Province Graduate Student Innovation Special Fund Project(YC2023-S642)。
文摘Rare earth molten salt electrolytic slag(RMES)has emerged as a promising secondary resource for rare earth elements(REEs).This study introduces an innovative leaching technique for extracting REEs from RMES under atmospheric conditions,employing an alkali phase reconstruction method followed by an acid leaching process.Additionally,the external electric field was employed to enhance the reaction.Under the optimal reaction conditions:NaOH initial concentration of 70 wt%,NaOH-slag mass ratio of 4:1,temperature of 160℃,current density of 1000 A/m^(2),reaction time of 90 min,stirring speed of 300 r/min,HCl concentration of 4 mol/L,liquid-solid ratio of 15:1,and leaching time of 20 min,the leaching efficiencies of Nd and Pr reach up to 99.21%and 99.14%,respectively.Phase analysis indicates that the rare earth fluorides transform into rare earth hydroxides,significantly enhancing their solubility in acid solution.The imposition of an external electric field leads to pronounced disruption of the RMES surface,thereby promoting the formation of stable reactive oxygen species in the alkaline medium.This facilitates the decomposition of fluorinated rare earths and hastens the phase reconstruction,resulting in an enhanced leaching process.The achieved leaching efficiency with an external electric field is 37%higher than that without an electric field.
基金Project supported by the National Key R&D Program"Solid Waste Recycling"Key Project(2020YFC1909000,2020YFC1909003)the National Natural Science Foundation of China(52064019)the Key Fund of Jiangxi Provincial Department of Science and Technology(2019ACBL20015)。
文摘A new process was proposed to extract rare earth elements(REEs),Li and F from electrolytic slag of rare earth molten salt by synergistic roasting and acid leaching.Firstly,the thermodynamic analysis of roasting reaction was carried out,then the effects of roasting factors on leaching REEs,Li and F in slag were investigated.In additions,the mineral phase and morphology of molten salt slag,roasting slag and acid leaching slag were characterized,and the migration mechanism of REES,Li and F minerals in roasting and leaching process was analyzed.The results show that the synergistic roasting and activation of molten salt slag by CaO and Al_(2)(SO_(4))_(3)are thermodynamically feasible.The optimum roasting conditions are as follows:molten salt slag of 20 g,Al_(2)(SO_(4))_(3)of 31.25 g and CaO of 6.25 g,roasting temperature of 1173.15 K and reaction time of 2 h,under this condition,the leaching rates of Nd,Pr,Gd,Li and F are 92.47%,91.56%,91.08%,96.69%and 96.8%,respectively.X-ray powder diffraction(XRD)and scanning electron microscopy-energy dispersive X-ray spectroscopy(SEM-EDS)analysis show that the rare earth fluoride(REF3)in molten salt slag transforms into soluble rare earth oxide(REO)after roasting and activation.After leaching,the leaching residue is mainly strip CaSO4,indicating that REES,Li and F can be fully extracted from molten salt slag.
基金Project supported by the National Key R&D Program of China(2020YFC1909003)。
文摘Due to the unique physical and chemical properties,rare earth elements(REEs)play a significant role in the high-tech field.In the past few decades,the rare earth reserve in China has been gradually decreasing and more pressure has been exerted on the global rare earth supply for the increasing demand of REEs,which indicates that it is essential to recycle secondary resources to meet the rare earth demand.As for rare earth molten salt electrolytic slag(REMES),although its high rare earth content has potential huge economic value,its high fluorine content of approximately 10 wt%-20 wt%can pollute the environment.Three methods are used to treat REMES.Hydro metallurgical and pyro-hydrometallurgical methods have gotten a big success for solving most of the hydrometallurgical problems,while some problems,like long route and waste water,need to be solved.Vacuum distillation is a new and promising method with a short process due to its harmlessness and high efficiency,but has shortcomings such as high energy consumption and material adaptability.This review presents these above three treatment methods,and the challenges and chances of using the recovery technique of REMES in an environmentally friendly way.
基金supported by the Longkou City Science and Technology Research and Development Plan(No.2020KJJH061).
文摘Developing supercapacitors(SCs)with long cycling life and wide operative voltage window is a significant topic in the field of aqueous electrolytes.Although the design of water in salt(WIS)electrolytes has pushed the development of aqueous electrolytes to a new height,the WIS electrolytes with an operative voltage window of up to 2.5 V is still very scarce.Herein,in order to enrich the type of aqueous electrolyte with high operative voltage,tetramethylammonium trifluoromethanesulfonate(TMAOTf)based WIS electrolyte was used as a model to construct WIS based hybrid electrolyte with acetonitrile(ACN)co-solvent and LiTFSI co-solute.In view of the coordination effect of ACN and Lit on free water in TMAOTf based WIS electrolyte,the TMAt-Lit-AWIS electrolyte has the electrochemical stabilization window of up to 3.35 V.Further coupled with the commercial YP-50F electrodes,TMAt-Lit-AWIS based SCs exhibited wide operative voltage window(2.5 V),long cycling life(45,000 cycles)and good low-temperature performance(99.99%capacitance retention after 2000 cycles at20℃).The design of this hybrid electrolyte will enrich the types of aqueous hybrid electrolytes with long cycling life and wide operative voltage window.
基金supported by the Strategic Priority Research Program of the Chinese Academy of Sciences(Grant No.XDA0400000)the One Hundred Person Project of the Chinese Academy of Sciences,the Shanghai Magnolia Talent Plan Pujiang Project(Grant No.23PJ1415600)the Shanghai International S&T Cooperation Program(Grant No.23160711700).
文摘Micro-sized silicon(mSi)anodes offer high capacity for next-generation lithium-ion batteries but suffer from severe volume changes,causing unstable interphases and poor cycling.Traditional electrolytes derive unstable electrolyte/electrolyte interphases,and flammable solvents pose safety risks.Here,we introduce a non-flammable molten salt electrolyte,which consists of lithium bis(fluorosulfonyl)imide,potassium bis(fluorosulfonyl)amide,and cesium bis(fluorosulfonyl)imide in a mole ratio of 0.3:0.35:0.35(noted as Li_(0.3)K_(0.35)Cs_(0.35)FSA),that forms an inorganic interphase on mSi,stabilizing the electrode/electrolyte interface.Computational and experimental insights elucidate the FSA-anion decomposition-derived SEI predominantly of LiF,Li_(3)N,Li_(2)O,and Li_(2)S,which exhibits mechanical resilience and low interfacial resistance,effectively accommodating the significant volume expansion of silicon during lithiation/delithiation.As a result,the Li||mSi half-cell achieves 60.7%capacity retention after 100 cycles with 99.5%average Coulombic efficiency.Overall,the Li_(0.3)K_(0.35)Cs_(0.35)FSA electrolyte eliminates flammability concerns while enabling robust cycling performance.This work demonstrates a safe,high-energy battery system by coupling mSi anodes with stable molten salt electrolytes,addressing both interfacial instability and safety challenges in mSi-based lithium-ion batteries.
基金supported by the National Natural Science Foundation of China(52272224 and 51902188)the Science Fund of Shandong Laboratory of Advanced Materials and Green Manufacturing at Yantai(AMGM2024F26)。
文摘Supercapacitors,also known as electrical double-layer capacitors(EDLCs),store and release electrical charge through the adsorption and desorption of ions on the surface of highly porous carbon materials[1].To meet the increasing demands from electric vehicles,rail traffic,military and space applications,EDLCs are usually required to operate within a broad temperature range(subzero to 60°C or more)[2].
基金This work was supported by the National Natural Science Foundation of China(Grant Nos.82103472,82202480,and 52372252)the Hunan Natural Science Fund for Distinguished Young Scholar(2021JJ10064)the Program of Youth Talent Support for Hunan Province(2020RC3011).
文摘Biocompatible devices are widely employed in modernized lives and medical fields in the forms of wearable and implantable devices,raising higher requirements on the battery biocompatibility,high safety,low cost,and excellent electrochemical performance,which become the evaluation criteria toward developing feasible biocompatible batteries.Herein,through conducting the battery implantation tests and leakage scene simulations on New Zealand rabbits,zinc sulfate electrolyte is proved to exhibit higher biosecurity and turns out to be one of the ideal zinc salts for biocompatible zinc-ion batteries(ZIBs).Furthermore,in order to mitigate the notorious dendrite growth and hydrogen evolution in mildly acidic electrolyte as well as improve their operating stability,Sn hetero nucleus is introduced to stabilize the zinc anode,which not only facilitates the planar zinc deposition,but also contributes to higher hydrogen evolution overpotential.Finally,a long lifetime of 1500 h for the symmetrical cell,the specific capacity of 150 mAh g^(-1)under 0.5 A g^(-1)for the Zn-MnO_(2)battery and 212 mAh g^(-1)under 5 A g^(-1)for the Zn—NH4V4O10 battery are obtained.This work may provide unique perspectives on biocompatible ZIBs toward the biosecurity of their cell components.
基金supported by the National Nature Science Associate Foundation (NSAF) of China (Grant No. U1930208)the Laboratory of Precision Manufacturing Technology+2 种基金China Academy of Engineering Physics (Grant No. ZD17006,ZM18002)the National Natural Science Foundation of China (Grant Nos. 11804312 and 21703215)the Science and Technology Innovation Foundation of Institute of Electronic Engineering (Grant No. S201904)。
文摘NiCl_(2) with high theoretical voltage and thermal decomposition temperature attracts much attention as cathode material for thermal batteries with the requirement of high power density, high energy density and long work time. Unfortunately, the practical utilization of thermal batteries with NiCl_(2) cathode is limited by their poor electrochemical performance under large current, even with the conventional Li F-Li Cl-Li Br all-lithium molten salt electrolyte which proposes ultrahigh lithium ion conductivity. In this work, an unexpected ionic exchange reaction between NiCl_(2) and Li Br in Li F-Li Cl-Li Br was found, which would be the main reason for the poor electrochemical behavior of thermal batteries with NiCl_(2) cathode and Li F-Li Cl-Li Br molten salt. On this basis, Li F-Li Cl-Li_(2)SO_(4), another all-lithium molten salt free of Li Br, was investigated as the new electrolyte for NiCl_(2) cathode. For the single cell of Li(Si)/Li F-Li Cl-Li_(2)SO_(4)/NiCl_(2), a discharge capacity of 377 mA h g^(-1)(with a cut-off voltage of 1.2 V) was achieved with large current density(500 mA cm^(-2)) applied at 520℃, which is almost twice of that of Li(Si)/Li F-Li Cl-Li Br/NiCl_(2)(190 mA h g^(-1)) at the same conditions.
基金the National Key R&D Program of China(No.2018YFB0905600)the National Natural Science Foundation of China(Nos.51874228 and U1766216)the Natural Science Foundation of Shaanxi Province,China(No.2020JM-068)。
文摘The Ca-Pb electrode couple is considered to be one of the least expensive(~36$/(k W·h))among various optional materials for liquid-metal batteries(LMBs).The electrochemical properties of Ca-Pb alloy in a Ca|Li Cl-Na Cl-Ca Cl_(2)|Pb cell were investigated in this paper.The electrode potential maintained a linear relationship in the current density range of 50-200 m A·cm^-2,which indicates that the alloying and dealloying processes of Ca with Pb attained rapid charge transfer and mass transport in the interface between the liquid electrode and electrolyte.The Ca-Pb electrode exhibited remarkable properties with a high discharge voltage of 0.6 V,a small self-discharge current density(<2 m A·cm^-2 at 600℃),and a high coulombic efficiency(>98.84%).The postmortem analysis showed that intermetallics Ca Pb3 and Ca Pb were uniformly distributed in the electrode with different molar fractions of Ca,which indicates that the nucleation of solid intermetallics did not hinder the diffusion of Ca in the electrode.This investigation on Ca-Pb electrode sheds light on the further research and the design of electrodes for Ca-based LMBs.
文摘The reduction of Ni(Ⅱ) is an irreversible reaction and La(Ⅲ) cannot be reduced to La directly but be co-deposited inductively in the present of Ni(Ⅱ) in the Acetamide-Urea-NaBr molten salt electrolyte at 353 K. The uncrystallized alloy film of La-Ni is obtained by potentiostatic electrolysis, and the amount of La grows with increasing cathodic overpotential, molar ratios of La(Ⅲ) to Ni(Ⅱ) and the electrolysis time. The maximum amount of La in alloy film reaches to 78.81% (mass fraction) in present study.
基金Project supported by the Beijing S&T Project,China(Grant No.Z13111000340000)the National Basic Research Program of China(Grant No.2012CB932900)the National Natural Science Foundation of China(Grants Nos.51325206 and 51421002)
文摘The cycling performance, impedance variation, and cathode surface evolution of the Li/LiCoO2 cell using Li FSI–KFSI molten salt electrolyte are reported. It is found that this battery shows poor cycling performance, with capacity retention of only about 67% after 20 cycles. It is essential to understand the origin of the instability. It is noticed that the polarization voltage and the impedance of the cell both increase slowly upon cycling. The structure and the properties of the pristine and the cycled LiCoO2 cathodes are investigated by x-ray diffraction（XRD）, scanning electron microscopy（SEM）, Raman spectroscopy, x-ray photoelectron spectroscopy（XPS）, and transmission electron microscopy（TEM）. It is found that the LiCoO2 particles are corroded by this molten salt electrolyte, and the decomposition by-product covers the surface of the LiCoO2 cathode after 20 cycles. Therefore, the surface side reaction explains the instability of the molten salt electrolyte with LiCoO2.
文摘Crystallized lithium fluoride(LiF)melts at 848℃ upon heating,and evaporates subsequently at a remarkably high temperature of 1673℃,characterizing its excellent thermally stability as one of the most representative metal halides.The marriage between Li F and rechargeable batteries dates back to early activities related to the electrochemical properties of lithium metal(Li°)negative electrodes,in which the nonaqueous electrolytes containing fluorinated salts were generally employed,e.g.,lithium tetrafluoroborate(LiBF_(4)),lithium hexafluoroarsenate(LiAsF_(6)),lithium trifluoromethanesulfonate(CF_(3)SO_(3)Li)[1].
