Lithium-sulfur(Li-S) batteries have generated significant attention due to their high theoretical specific capacity and energy density among a host of energy storage power devices.Nevertheless,the lithium polysulfide ...Lithium-sulfur(Li-S) batteries have generated significant attention due to their high theoretical specific capacity and energy density among a host of energy storage power devices.Nevertheless,the lithium polysulfide dissolution shuttle that occurs within Li-S batteries will lead to capacity deterioration and inadequate cycling stability.In the paper,we proposed a measure to deal with the above problems by modifying the separator with Nd_(2)O_(3)/graphene composite in Li-S batteries.Graphene's special chemical properties and structural qualities make it an excellent choice for Li-S batteries.Meanwhile,Nd_(2)O_(3) has a strong binding affinity with lithium polysulfide due to its low electronegativity,which exhibits Lewis' s acidity and forms strong interactions with lithium polysulfide,which is strongly Lewis basic.By utilizing these advantageous properties,Li-S batteries assembling Nd_(2)O_(3)-decorated reduced graphite oxide modified polypropylene separators(Nd_(2)O_(3)/RGO/PP) demonstrate outstanding electrochemical performance,including a mere 0.0525% capacity attenuation rate under 2C during 1000 cycles and with exceptional rate performance of 614 mAh/g even at 3C.This study presents valuable knowledge for effectively modifying separators using rare earth oxides to incorporate graphene,ultimately promoting the practical application of Li-S batteries.展开更多
By combining the mass transfer mechanism of neodymium oxide with dissolution kinetics,a solution strategy for neodymium oxide dissolution was proposed to predict the dissolved neodymium oxide concentration during the ...By combining the mass transfer mechanism of neodymium oxide with dissolution kinetics,a solution strategy for neodymium oxide dissolution was proposed to predict the dissolved neodymium oxide concentration during the process under complex flow field conditions.The factors affecting neodymium oxide dissolution were analyzed in detail.Aiming at the pulse feeding and continuous feeding modes in industrial practice,the characteristics of the dissolution process under the two feeding modes were compared.Simulation results showed that pulse feeding took shorter time to distribute evenly than continuous feeding.Finally,the dissolution time of single-particle neodymium oxide under static flow field conditions was compared with the literature results.Except for only one set of data with a maximum error of about 10%,the errors of other data are all within 5%.展开更多
A simple and economical chemical process for obtaining high purity neodymium oxide is discussed. The raw material in the form of RE （rare earth） carbonates is produced industrially in Brazil from monazite. Using thi...A simple and economical chemical process for obtaining high purity neodymium oxide is discussed. The raw material in the form of RE （rare earth） carbonates is produced industrially in Brazil from monazite. Using this concentrate as the feed material, ion exchange with a strong cationic resin, commonly used for water treatment, and without the use of retention ions was used for the fractionating of the REE （rare earth elements）. The eluent was ammonium salt of EDTA （ethylenediaminetetraacetic acid） at pH 4.0. The complex of EDTA-neodymium was transformed into neodymium oxides via oxalate precipitation. We produced 99.9% pure Nd203 in yields greater than or equal to 80%. Molecular absorption spectrophotometry was used to monitor the neodymium content during the process and sector field inductively coupled plasma mass spectrometry was used to certify the purity of the neodymium oxides. The typical neodymium oxides obtained contained the followings contaminants in micrograms per gram： Sc （4.09）; Y （0.39）; La （0.78）; Ce （5.62）; Pr （4.56）; Sm （11.10）; Eu （1.10）; Gd （14.30）; Tb （29.3）; Dy （4.15）; Ho （8.39）; Er （13.80）; Tm （0.23）; Yb （2.29）; Lu （0.39）. High purity neodymium oxides obtained from this procedure replaced the imported product used in research and development work on rare earth at IPEN/CNEN-SP （Instituto de Pesquisas Energeticas e Nucleares/Comissfio Nacional de Eneergia Nuclear-Sao Paulo）.展开更多
Neodymium chromium oxide(NdCrO_(3))and NdCrO_(3)/graphene oxide(GO)nanocomposite were synthesized via sol-gel and co-precipitation techniques for being used in high-perfo rmance supercapacitors and for the possible ap...Neodymium chromium oxide(NdCrO_(3))and NdCrO_(3)/graphene oxide(GO)nanocomposite were synthesized via sol-gel and co-precipitation techniques for being used in high-perfo rmance supercapacitors and for the possible application in ultraviolet(UV)materials.Herein the systematic synthesis approach was adopted,which enhances the optical and electrical properties of the grown wide band-gap composite nanomaterial.Structural characterization of the grown materials was attempted using X-ray diffraction(XRD)and scanning electron microscopy(SEM).Most importantly the electrochemical analysis of the grown samples was carried out by employing a glassy carbon electrode and 3 mol/L KOH electrolyte,which demonstrates significant improvements in a specific capacitance of approximately360 F/g,an energy density of approximately 18 Wh/kg,and a maximum power density of approximately 257 W/kg,respectively.Moreover,NdCrO_(3)/GO nanocomposite maintains a cyclic stability of 97.6%after4000 cycles.Photoluminescence(PL)spectroscopy confirms the wide bandgap nature of the NdCrO_(3)and NdCrO_(3)/GO nanocomposite,indicating its potential application in UVC devices.These findings emphasize the potential of the NdCrO_(3)/GO nanocomposite in advancing efficient energy storage solutions and the possibility of being used in UVC technology.展开更多
Nanocrystalline indium oxide powders were prepared by microemulsion and then Y2O3 and Nd2O3 doped In2O3 were synthesized separately by impregnation and chemical co-deposition. The structure and morphology were charact...Nanocrystalline indium oxide powders were prepared by microemulsion and then Y2O3 and Nd2O3 doped In2O3 were synthesized separately by impregnation and chemical co-deposition. The structure and morphology were characterized by XRD and TEM, respectively. Gas sensing properties were tested at static state. The results show that homogeneous indium oxide nanopowder with main grain size of 20 nm can be obtained from microemulsion after sintered at 600 ℃ for 1 h. Pure indium oxide gas sensor has higher sensitivity to gasoline than that to ethanol, HCHO, C6H6, NH3, C4H10, but the selectivity is not as well as sensitivity.展开更多
The oxidation behaviours of pure 77,Ti-11 at% Al and Ti-11 at% Al-Nd alloys in air at the tempera- ture range 800～1000℃ have been investigated in the present paper.Their oxidation kinetics follows substantially the ...The oxidation behaviours of pure 77,Ti-11 at% Al and Ti-11 at% Al-Nd alloys in air at the tempera- ture range 800～1000℃ have been investigated in the present paper.Their oxidation kinetics follows substantially the parabolic rate law.The activation energies of oxidation processes are 103 and 91 kcal/mole for Ti-11 Al and Ti-11 Al-Nd alloys,respectively.The platinum wire tagging tests have shown that oxygen atoms diffuse into the substrate during oxidation of pure Ti and that Ti,Al and Nd atoms diffuse across a scale of oxides outwards during oxidations of these alloys.Nd addition promotes the selective oxidation of aluminium.The addition of Al and Nd decreases the extent of penetration of oxygen atoms into the Ti substrate.The X-ray diffraction analysis confirms that the oxide scales of the alloys consist of TiO_2 and α-Al_2O_3,or TiO_2,α-Al_2O_3 and a small amount of Nd_2O_3 for Ti-11 Al and Ti-11 Al-Nd alloys, respectively.展开更多
Application of amorphous V2O5/carbon/ncodymium oxide （Nd2O3） composite is one ot ways to surmount me lower electrical conductivity of V2O5. A new type of V2O5/carbon/Nd2O3 composite was prepared by mixing vanadium o...Application of amorphous V2O5/carbon/ncodymium oxide （Nd2O3） composite is one ot ways to surmount me lower electrical conductivity of V2O5. A new type of V2O5/carbon/Nd2O3 composite was prepared by mixing vanadium oxide hydrosol, acetone, carbon and Nd2O3 powder. High rate discharge/charge property of the composite electrode was tested electrochemically. This composite with Nd2O3 added shows the improvement of not only the discharge capacity but also cycle durability discharge capacity. The rate capability of the composite cathode also increases with the addition of Nd2O3. Even at 10 A·g^-1 current density, a capacity of about 250 mAh·g^-1 was obtained at 25 ℃. This enhanced rate capability and cycle life are probably caused by the increase in porosity of open pores and short diffusion length of the active material on the lithium-ion insertion.展开更多
基金Project supported by Guangzhou Science and Technology Project,China (201803020038)Guangdong Science and Technology Commissioner Project (GDKTP2020046700)Innovation and Entrepreneurship Training Program for University Students (202324040)。
文摘Lithium-sulfur(Li-S) batteries have generated significant attention due to their high theoretical specific capacity and energy density among a host of energy storage power devices.Nevertheless,the lithium polysulfide dissolution shuttle that occurs within Li-S batteries will lead to capacity deterioration and inadequate cycling stability.In the paper,we proposed a measure to deal with the above problems by modifying the separator with Nd_(2)O_(3)/graphene composite in Li-S batteries.Graphene's special chemical properties and structural qualities make it an excellent choice for Li-S batteries.Meanwhile,Nd_(2)O_(3) has a strong binding affinity with lithium polysulfide due to its low electronegativity,which exhibits Lewis' s acidity and forms strong interactions with lithium polysulfide,which is strongly Lewis basic.By utilizing these advantageous properties,Li-S batteries assembling Nd_(2)O_(3)-decorated reduced graphite oxide modified polypropylene separators(Nd_(2)O_(3)/RGO/PP) demonstrate outstanding electrochemical performance,including a mere 0.0525% capacity attenuation rate under 2C during 1000 cycles and with exceptional rate performance of 614 mAh/g even at 3C.This study presents valuable knowledge for effectively modifying separators using rare earth oxides to incorporate graphene,ultimately promoting the practical application of Li-S batteries.
基金financial supports from the Jiangxi Ionic Rare Earth Resources Green Development and High-value Utilization of State Key Laboratory Cultivation Program,China (No.20194AFD44003)the Jiangxi Province Key Innovation Research and Development Platform Plan,China (No.20181BCD40009)。
文摘By combining the mass transfer mechanism of neodymium oxide with dissolution kinetics,a solution strategy for neodymium oxide dissolution was proposed to predict the dissolved neodymium oxide concentration during the process under complex flow field conditions.The factors affecting neodymium oxide dissolution were analyzed in detail.Aiming at the pulse feeding and continuous feeding modes in industrial practice,the characteristics of the dissolution process under the two feeding modes were compared.Simulation results showed that pulse feeding took shorter time to distribute evenly than continuous feeding.Finally,the dissolution time of single-particle neodymium oxide under static flow field conditions was compared with the literature results.Except for only one set of data with a maximum error of about 10%,the errors of other data are all within 5%.
文摘A simple and economical chemical process for obtaining high purity neodymium oxide is discussed. The raw material in the form of RE （rare earth） carbonates is produced industrially in Brazil from monazite. Using this concentrate as the feed material, ion exchange with a strong cationic resin, commonly used for water treatment, and without the use of retention ions was used for the fractionating of the REE （rare earth elements）. The eluent was ammonium salt of EDTA （ethylenediaminetetraacetic acid） at pH 4.0. The complex of EDTA-neodymium was transformed into neodymium oxides via oxalate precipitation. We produced 99.9% pure Nd203 in yields greater than or equal to 80%. Molecular absorption spectrophotometry was used to monitor the neodymium content during the process and sector field inductively coupled plasma mass spectrometry was used to certify the purity of the neodymium oxides. The typical neodymium oxides obtained contained the followings contaminants in micrograms per gram： Sc （4.09）; Y （0.39）; La （0.78）; Ce （5.62）; Pr （4.56）; Sm （11.10）; Eu （1.10）; Gd （14.30）; Tb （29.3）; Dy （4.15）; Ho （8.39）; Er （13.80）; Tm （0.23）; Yb （2.29）; Lu （0.39）. High purity neodymium oxides obtained from this procedure replaced the imported product used in research and development work on rare earth at IPEN/CNEN-SP （Instituto de Pesquisas Energeticas e Nucleares/Comissfio Nacional de Eneergia Nuclear-Sao Paulo）.
基金support from the Deanship of Scientific Research at King Khalid University,Saudi Arabia(RGP2/505/45)。
文摘Neodymium chromium oxide(NdCrO_(3))and NdCrO_(3)/graphene oxide(GO)nanocomposite were synthesized via sol-gel and co-precipitation techniques for being used in high-perfo rmance supercapacitors and for the possible application in ultraviolet(UV)materials.Herein the systematic synthesis approach was adopted,which enhances the optical and electrical properties of the grown wide band-gap composite nanomaterial.Structural characterization of the grown materials was attempted using X-ray diffraction(XRD)and scanning electron microscopy(SEM).Most importantly the electrochemical analysis of the grown samples was carried out by employing a glassy carbon electrode and 3 mol/L KOH electrolyte,which demonstrates significant improvements in a specific capacitance of approximately360 F/g,an energy density of approximately 18 Wh/kg,and a maximum power density of approximately 257 W/kg,respectively.Moreover,NdCrO_(3)/GO nanocomposite maintains a cyclic stability of 97.6%after4000 cycles.Photoluminescence(PL)spectroscopy confirms the wide bandgap nature of the NdCrO_(3)and NdCrO_(3)/GO nanocomposite,indicating its potential application in UVC devices.These findings emphasize the potential of the NdCrO_(3)/GO nanocomposite in advancing efficient energy storage solutions and the possibility of being used in UVC technology.
文摘Nanocrystalline indium oxide powders were prepared by microemulsion and then Y2O3 and Nd2O3 doped In2O3 were synthesized separately by impregnation and chemical co-deposition. The structure and morphology were characterized by XRD and TEM, respectively. Gas sensing properties were tested at static state. The results show that homogeneous indium oxide nanopowder with main grain size of 20 nm can be obtained from microemulsion after sintered at 600 ℃ for 1 h. Pure indium oxide gas sensor has higher sensitivity to gasoline than that to ethanol, HCHO, C6H6, NH3, C4H10, but the selectivity is not as well as sensitivity.
基金This work was financially supported by the Corrosion Science Laboratory,Academia Sinica
文摘The oxidation behaviours of pure 77,Ti-11 at% Al and Ti-11 at% Al-Nd alloys in air at the tempera- ture range 800～1000℃ have been investigated in the present paper.Their oxidation kinetics follows substantially the parabolic rate law.The activation energies of oxidation processes are 103 and 91 kcal/mole for Ti-11 Al and Ti-11 Al-Nd alloys,respectively.The platinum wire tagging tests have shown that oxygen atoms diffuse into the substrate during oxidation of pure Ti and that Ti,Al and Nd atoms diffuse across a scale of oxides outwards during oxidations of these alloys.Nd addition promotes the selective oxidation of aluminium.The addition of Al and Nd decreases the extent of penetration of oxygen atoms into the Ti substrate.The X-ray diffraction analysis confirms that the oxide scales of the alloys consist of TiO_2 and α-Al_2O_3,or TiO_2,α-Al_2O_3 and a small amount of Nd_2O_3 for Ti-11 Al and Ti-11 Al-Nd alloys, respectively.
文摘Application of amorphous V2O5/carbon/ncodymium oxide （Nd2O3） composite is one ot ways to surmount me lower electrical conductivity of V2O5. A new type of V2O5/carbon/Nd2O3 composite was prepared by mixing vanadium oxide hydrosol, acetone, carbon and Nd2O3 powder. High rate discharge/charge property of the composite electrode was tested electrochemically. This composite with Nd2O3 added shows the improvement of not only the discharge capacity but also cycle durability discharge capacity. The rate capability of the composite cathode also increases with the addition of Nd2O3. Even at 10 A·g^-1 current density, a capacity of about 250 mAh·g^-1 was obtained at 25 ℃. This enhanced rate capability and cycle life are probably caused by the increase in porosity of open pores and short diffusion length of the active material on the lithium-ion insertion.
