new method is proposed for the recovery of Mn via the direct electrochemical reduction of LiMn_(2)O_(4) from the waste of lithium-ion batteries in NaCl−CaCl_(2) melts at 750°C.The results show that the LiMn_(2)O_...new method is proposed for the recovery of Mn via the direct electrochemical reduction of LiMn_(2)O_(4) from the waste of lithium-ion batteries in NaCl−CaCl_(2) melts at 750°C.The results show that the LiMn_(2)O_(4) reduction process by the electrochemical method on the coated electrode surface occurs in three steps:Mn(IV)→Mn(III)→Mn(II)→Mn.The products of this electro-deoxidation are CaMn2O4,MnO,(MnO)x(CaO)1−x,and Mn.Metal Mn appears when the electrolytic voltage increases to 2.6 V,which indicates that increasing the voltage may promote the deoxidation reaction process.With the advancement of the three-phase interline(3PI),electric deoxygenation gradually proceeds from the outer area of the crucible to the core.At high voltage,the kinetic process of the reduction reaction is accelerated,which generates double 3PIs at different stages.展开更多
Vanadium pentoxide xerogel films used for lithium rechargeable batteries were prepared from crystalline c-V2O5 by melt quenching method,then the electrochemical process of lithium intercalation into vanadium pentoxide...Vanadium pentoxide xerogel films used for lithium rechargeable batteries were prepared from crystalline c-V2O5 by melt quenching method,then the electrochemical process of lithium intercalation into vanadium pentoxide xerogel films was simulated with an equivalent circuit model, which was derived from the mechanism of electrode reactions. Measured electrochemical impedance spectra at various electrode potentials were analyzed by using the complex non-linear least-squares fitting method. The results show that impedance spectra consist of 2 high-to- medium frequency depressed arcs and a low frequency straight line. The high frequency arc is attributed to the absorption reaction of lithium ions into the oxide film, the medium frequency arc is attributed to the charge transfer reaction at the vanadium oxide/electrolyte interface and the low frequency is characterized by a straight line with a phase angle of 45° corresponding to the diffusion of lithium ion through vanadium oxide phase. The experimental and calculated results are compared and discussed focusing on the electrochemical performance and the state of charge of the electrode. Moreover, the high consistence of the fitted values of the model to the experimental data indicates that this mathematical model does give a satisfying description of the intercalation process of vanadium pentoxide xerogel films.展开更多
The surface of as-prepared LiMn2O4 was modified with ZnO, Al2O3, CoO and LiCoO2 using a simple nitrate melting impregnation method. Transmission electron microscopy （TEM） studies indicated that oxide nano- particles...The surface of as-prepared LiMn2O4 was modified with ZnO, Al2O3, CoO and LiCoO2 using a simple nitrate melting impregnation method. Transmission electron microscopy （TEM） studies indicated that oxide nano- particles in the range of 10～50 nm are coated on the surface of the spinel. The surface modified samples show better capacity retention than the unmodified LiMn2O4 spinel at both room temperature and 55℃. Among these samples, the ZnO-modified LiMn2O4 shows the best combination of a high capacity and a low capacity fading rate of 0.036% per cycle at room temperature and 0.064% per cycle at 55℃. The improvement for surface modified LiMn2O4 can be attributed to the inhibition of Mn dissolution and O losses on the surface.展开更多
Some transition metal antimonides were prepared by levitation melting and subsequent ball-milling. The electrochem-ical behaviors of these materials as new candidate negative electrode materials in lithium ion seconda...Some transition metal antimonides were prepared by levitation melting and subsequent ball-milling. The electrochem-ical behaviors of these materials as new candidate negative electrode materials in lithium ion secondary batteries wereinvestigated. It was found that they exhibited significantly larger volumetric capacity than carbon-based materi-als. The formation and composition of solid electrolyte interface (SEI) film were characterized by electrochemicalimpedance spectroscopy (EIS) and Fourier transform infra-red (FTIR) spectroscopy.展开更多
The aim of this work was to investigate the effect of lithium chloride (LiCl) on the fibre length distribution, melting temperature and the rheological characteristics of high yield pulp fibre reinforced polyamide bio...The aim of this work was to investigate the effect of lithium chloride (LiCl) on the fibre length distribution, melting temperature and the rheological characteristics of high yield pulp fibre reinforced polyamide biocomposite. The inorganic salt lithium chloride (LiCl) was used to decrease the melting and processing temperature of bio-based polyamide 11. The extrusion method and Brabender mixer approaches were used to carry out the compounding process. The densities and fibre content were found to be increased after processing using both compounding methods. The HYP fibre length distribution analysis realized using the FQA equipment showed an important fibre-length reduction after processing by both techniques. The rheological properties of HYP-reinforced net and modified bio-based polyamide 11 “PA11” (HYP/PA11) composite were investigated using a capillary rheometer. The rheological tests were performed in function of the shear rate for different temperature conditions. The low-temperature process compounding had higher shear viscosity;this was because during the process the temperature was low and the mixing and melting were induced by the high shear rate created during compounding process. Experimental test results using the extrusion process showed a steep decrease in shear viscosity with increasing shear rate, and this melt-flow characteristic corresponds to shear-thinning behavior in HYP/PA11, and this steep decrease in the melt viscosity can be associated to the hydrolyse reaction of nylon for high pulp fibre moisture content at high temperature. In addition to the low processing temperature, the melt viscosity of the biocomposite using the Brabender mixer approach increases with increasing shear rate, and this stability in the increase even at high shear rate for high pulp moisture content is associated to the presence of inorganic salt lithium chloride which creates the hydrogen bonds with pulp during the compounding process.展开更多
Lithium(Li)is a promising candidate for nextgeneration battery anode due to its high theoretical specific capacity and low reduction potential.However,safety issues derived from the uncontrolled growth of Li dendrite ...Lithium(Li)is a promising candidate for nextgeneration battery anode due to its high theoretical specific capacity and low reduction potential.However,safety issues derived from the uncontrolled growth of Li dendrite and huge volume change of Li hinder its practical application.C onstructing dendrite-free composite Li anodes can significantly alleviate the above problems.Copper(Cu)-based materials have bee n widely used as substrates of the composite electrodes due to their chemical stability,excellent conductivity,and good mechanical strength.Copper/lithium(Cu/Li)composite anodes significantly regulate the local current density and decrease Li nucleation overp otential,realizing the uniform and dendrite-free Li deposition.In this review,Cu/Li composite methods including electrodeposition,melting infusion,and mechanical rolling are systematically summarized and discussed.Additionally,design strategies of Cu-based current collectors for high performance Cu/Li composite anodes are illustrated.General challenges and future development for Cu/Li composite anodes are presented and postulated.We hope that this review can provide a comprehensive understanding of Cu/Li composite methods of the latest development of Li metal anode and stimulate more research in the future.展开更多
基金the National Nat-ural Science Foundation of China(No.51774143).
文摘new method is proposed for the recovery of Mn via the direct electrochemical reduction of LiMn_(2)O_(4) from the waste of lithium-ion batteries in NaCl−CaCl_(2) melts at 750°C.The results show that the LiMn_(2)O_(4) reduction process by the electrochemical method on the coated electrode surface occurs in three steps:Mn(IV)→Mn(III)→Mn(II)→Mn.The products of this electro-deoxidation are CaMn2O4,MnO,(MnO)x(CaO)1−x,and Mn.Metal Mn appears when the electrolytic voltage increases to 2.6 V,which indicates that increasing the voltage may promote the deoxidation reaction process.With the advancement of the three-phase interline(3PI),electric deoxygenation gradually proceeds from the outer area of the crucible to the core.At high voltage,the kinetic process of the reduction reaction is accelerated,which generates double 3PIs at different stages.
文摘Vanadium pentoxide xerogel films used for lithium rechargeable batteries were prepared from crystalline c-V2O5 by melt quenching method,then the electrochemical process of lithium intercalation into vanadium pentoxide xerogel films was simulated with an equivalent circuit model, which was derived from the mechanism of electrode reactions. Measured electrochemical impedance spectra at various electrode potentials were analyzed by using the complex non-linear least-squares fitting method. The results show that impedance spectra consist of 2 high-to- medium frequency depressed arcs and a low frequency straight line. The high frequency arc is attributed to the absorption reaction of lithium ions into the oxide film, the medium frequency arc is attributed to the charge transfer reaction at the vanadium oxide/electrolyte interface and the low frequency is characterized by a straight line with a phase angle of 45° corresponding to the diffusion of lithium ion through vanadium oxide phase. The experimental and calculated results are compared and discussed focusing on the electrochemical performance and the state of charge of the electrode. Moreover, the high consistence of the fitted values of the model to the experimental data indicates that this mathematical model does give a satisfying description of the intercalation process of vanadium pentoxide xerogel films.
文摘The surface of as-prepared LiMn2O4 was modified with ZnO, Al2O3, CoO and LiCoO2 using a simple nitrate melting impregnation method. Transmission electron microscopy （TEM） studies indicated that oxide nano- particles in the range of 10～50 nm are coated on the surface of the spinel. The surface modified samples show better capacity retention than the unmodified LiMn2O4 spinel at both room temperature and 55℃. Among these samples, the ZnO-modified LiMn2O4 shows the best combination of a high capacity and a low capacity fading rate of 0.036% per cycle at room temperature and 0.064% per cycle at 55℃. The improvement for surface modified LiMn2O4 can be attributed to the inhibition of Mn dissolution and O losses on the surface.
基金This work is supported by the N ational Natural Science Foundation of China(No.50201014)RFDP of the Education Ministry of China(No.20010335045).
文摘Some transition metal antimonides were prepared by levitation melting and subsequent ball-milling. The electrochem-ical behaviors of these materials as new candidate negative electrode materials in lithium ion secondary batteries wereinvestigated. It was found that they exhibited significantly larger volumetric capacity than carbon-based materi-als. The formation and composition of solid electrolyte interface (SEI) film were characterized by electrochemicalimpedance spectroscopy (EIS) and Fourier transform infra-red (FTIR) spectroscopy.
文摘The aim of this work was to investigate the effect of lithium chloride (LiCl) on the fibre length distribution, melting temperature and the rheological characteristics of high yield pulp fibre reinforced polyamide biocomposite. The inorganic salt lithium chloride (LiCl) was used to decrease the melting and processing temperature of bio-based polyamide 11. The extrusion method and Brabender mixer approaches were used to carry out the compounding process. The densities and fibre content were found to be increased after processing using both compounding methods. The HYP fibre length distribution analysis realized using the FQA equipment showed an important fibre-length reduction after processing by both techniques. The rheological properties of HYP-reinforced net and modified bio-based polyamide 11 “PA11” (HYP/PA11) composite were investigated using a capillary rheometer. The rheological tests were performed in function of the shear rate for different temperature conditions. The low-temperature process compounding had higher shear viscosity;this was because during the process the temperature was low and the mixing and melting were induced by the high shear rate created during compounding process. Experimental test results using the extrusion process showed a steep decrease in shear viscosity with increasing shear rate, and this melt-flow characteristic corresponds to shear-thinning behavior in HYP/PA11, and this steep decrease in the melt viscosity can be associated to the hydrolyse reaction of nylon for high pulp fibre moisture content at high temperature. In addition to the low processing temperature, the melt viscosity of the biocomposite using the Brabender mixer approach increases with increasing shear rate, and this stability in the increase even at high shear rate for high pulp moisture content is associated to the presence of inorganic salt lithium chloride which creates the hydrogen bonds with pulp during the compounding process.
基金supported by the National Key Research and Development Program of China(No.2021YFB2500200)the National Natural Science Foundation of China(No.52302243)China Postdoctoral Science Foundation(Nos.2022M721029 and 2022M721030)。
文摘Lithium(Li)is a promising candidate for nextgeneration battery anode due to its high theoretical specific capacity and low reduction potential.However,safety issues derived from the uncontrolled growth of Li dendrite and huge volume change of Li hinder its practical application.C onstructing dendrite-free composite Li anodes can significantly alleviate the above problems.Copper(Cu)-based materials have bee n widely used as substrates of the composite electrodes due to their chemical stability,excellent conductivity,and good mechanical strength.Copper/lithium(Cu/Li)composite anodes significantly regulate the local current density and decrease Li nucleation overp otential,realizing the uniform and dendrite-free Li deposition.In this review,Cu/Li composite methods including electrodeposition,melting infusion,and mechanical rolling are systematically summarized and discussed.Additionally,design strategies of Cu-based current collectors for high performance Cu/Li composite anodes are illustrated.General challenges and future development for Cu/Li composite anodes are presented and postulated.We hope that this review can provide a comprehensive understanding of Cu/Li composite methods of the latest development of Li metal anode and stimulate more research in the future.
