A novel SnO2-based gas anode was developed for aluminum electrolysis in molten cryolite at 850 ＆#176;C to reduce energy consumption and decrease CO2 emissions. Hydrogen was introduced into the anode, participating in...A novel SnO2-based gas anode was developed for aluminum electrolysis in molten cryolite at 850 ＆#176;C to reduce energy consumption and decrease CO2 emissions. Hydrogen was introduced into the anode, participating in the anode reaction. Carbon and aluminum were used as the cathode and reference electrodes, respectively. Cyclic voltammetry was applied in the cell to investigate the electrochemical behavior of oxygen ion on platinum and SnO2-based materials. The potential for oxygen evolution on these electrode materials was determined. Then, galvanostatic electrolysis was performed on the gas anode, showing a significant depolarization effect （a decrease of ~0.8 V of the anode potential） after the introduction of hydrogen, compared with no gas introduction or the introduction of argon. The results indicate the involvement of hydrogen in the anode reaction （three-phase-boundary reaction including gas, electrolyte and electrode） and give the possibility for the utilization of reducing gas anodes for aluminum electrolysis.展开更多
Although metal oxide compounds are considered as desirable anode materials for potassium-ion batteries(PIBs)due to their high theoretical capacity,the large volume variation remains a key issue in realizing metal oxid...Although metal oxide compounds are considered as desirable anode materials for potassium-ion batteries(PIBs)due to their high theoretical capacity,the large volume variation remains a key issue in realizing metal oxide anodes with long cycle life and excellent rate property.In this study,polypyrroleencapsulated Sb_(2)WO_(6)(denoted Sb_(2)WO_(6)@PPy)microflowers are synthesized by a one-step hydrothermal method followed by in-situ polymerization and coating by pyrrole.Leveraging the nanosheet-stacked Sb_(2)WO_(6)microflower structure,the improved electronic conductivity,and the architectural protection offered by the PPy coating,Sb_(2)WO_(6)@PPy exhibits boosted potassium storage properties,thereby demonstrating an outstanding rate property of 110.3 m A h g^(-1)at 5 A g^(-1)and delivering a long-period cycling stability with a reversible capacity of 197.2 m A h g^(-1)after 500 cycles at 1 A g^(-1).In addition,the conversion and alloying processes of Sb_(2)WO_(6)@PPy in PIBs with the generation of intermediates,K_(2)WO_(4)and K_(3)Sb,is determined by X-ray photoelectron spectroscopy,transmission electron microscopy,and exsitu X-ray diffraction during potassiation/depotassiation.Density functional theory calculations demonstrate that the robust coupling between PPy and Sb_(2)WO_(6)endues it with a much stronger total density of states and a built-in electric field,thereby increasing the electronic conductivity,and thus effectively reduces the K^(+)diffusion barrier.展开更多
It is urgent to solve the problems of the dramatic volume expansion and pulverization of SnO_2 anodes during cycling process in battery systems. To address this issue, we design a hybrid structure of N-doped carbon fi...It is urgent to solve the problems of the dramatic volume expansion and pulverization of SnO_2 anodes during cycling process in battery systems. To address this issue, we design a hybrid structure of N-doped carbon fibers@SnO_2 nanoflowers(NC@SnO_2) to overcome it in this work. The hybrid NC@SnO_2 is synthesized through the hydrothermal growth of SnO_2 nanoflowers on the surface of N-doped carbon fibers obtained by electrospinning. The NC is introduced not only to provide a support framework in guiding the growth of the SnO_2 nanoflowers and prevent the flower-like structures from agglomeration, but also serve as a conductive network to accelerate electronic transmission along one-dimensional structure effectively. When the hybrid NC@SnO_2 was served as anode, it exhibits a high discharge capacity of 750 Ah g^(-1) at 1 A g^(-1) after 100 cycles in Li-ion battery and 270 mAh g^(-1) at 100 mA g^(-1) for 100 cycles in Na-ion battery, respectively.展开更多
A new SnO2-Fe2O3/SWCNTs（single-walled carbon nanotubes） ternary nanocomposite was first synthesized by a facile hydrothermal approach.SnO2 and Fe2O3 nanoparticles（NPs） were homogeneously located on the surface of ...A new SnO2-Fe2O3/SWCNTs（single-walled carbon nanotubes） ternary nanocomposite was first synthesized by a facile hydrothermal approach.SnO2 and Fe2O3 nanoparticles（NPs） were homogeneously located on the surface of SWCNTs,as confirmed by X-ray diffraction（XRD）,transmission electron microscope（TEM） and energy dispersive X-ray spectroscopy（EDX）.Due to the synergistic effect of different components,the as synthesized SnO2-Fe2O3/SWCNTs composite as an anode material for lithium-ion batteries exhibited excellent electrochemical performance with a high capacity of 692 mAh·g-1 which could be maintained after 50 cycles at 200 mA·g-1.Even at a high rate of2000 mA·g-1,the capacity was still remained at 656 mAh·g-1.展开更多
TiO2-coated SnO2 （TCS） hollow spheres, which are new anode materials for lithium ion （Li-ion） batteries, were prepared and characterized with X-ray diffraction （XRD）, scanning electron microscopy （SEM）, transm...TiO2-coated SnO2 （TCS） hollow spheres, which are new anode materials for lithium ion （Li-ion） batteries, were prepared and characterized with X-ray diffraction （XRD）, scanning electron microscopy （SEM）, transmission electron microscopy （TEM）, cyclic voltammetry （CV）, and galvanostatic charge/discharge tests. The results obtained from XRD, SEM, and TEM show that TiO2 can be uniforrrdy coated on the surface of SnO2 hollow spheres with the assistance of anionic surfactant. The cyclic voltammograms indicate that both TiO2 and SnO2 exhibit the activity for Li-ion storage. The charge/discharge tests show that the prepared TCS hollow spheres have a higher reversible coulomb efficiency and a better cycling stability than the uncoated SnO2 hollow spheres.展开更多
Stainless steel plates were successfully coated with SnO2-CeO2 films （SS/SnO2-CeO2） by brush coating with a solution of stannous chloride and cerium trichloride followed by thermal decomposition. It is proven that t...Stainless steel plates were successfully coated with SnO2-CeO2 films （SS/SnO2-CeO2） by brush coating with a solution of stannous chloride and cerium trichloride followed by thermal decomposition. It is proven that the properties of SnO2 films can be evidently improved by Ce doping, and 600℃ is the optimum temperature to prepare SS/SnO2-CeO2 anodes. The physicochemical and electrochemical properties as well as the elec- trocatalytic activity of the electrodes were investigated. It is found that the novel electrodes have compact microstructure, high overpotential for oxygen evolution （1.60 V vs SCE）, excellent electrochemical stability, relatively low cost and excellent catalytic activity for oxidizing pollutants. An industrial dye wastewater, which is hard to be purified by using conventional chemical flocculation methods, was oxidated by employing the SS/SnO2-CeO2 anodes, and 83.00% of color and 48.62% of chemical oxygen demand （COD） removal was achieved under the cell voltage of 5 V within only 2 min, and the electricity consumption is only 1.83 kWh for oxidizing I m3 of dye wastewater.展开更多
Well-dispersed SnO2 nanorods with diameter of 4-15 nm and length of 100-200 nm are synthesised through a hydrothermal route and their potential as anode materials in lithium-ion batteries is investigated. The observed...Well-dispersed SnO2 nanorods with diameter of 4-15 nm and length of 100-200 nm are synthesised through a hydrothermal route and their potential as anode materials in lithium-ion batteries is investigated. The observed initial discharge capacity is as high as 1778 mA.h/g, much higher than the theoretical value of the bulk SnO2 （1494 mA.h/g）. During the following 15 cycles, the reversible capacity decreases from 929 to 576 mA-h/g with a fading rate of 3.5% per cycle. The fading mechanism is discussed. Serious capacity fading can be avoided by reducing the cycling voltages from 0.05-3.0 to 0.4-1.2 V. At the end, SnO2 nanorods with much smaller size are synthesized and their performance as anode materials is studied. The size effect on the electrochemical properties is briefly discussed.展开更多
We demonstrate a facile route for the massive production of SnCb/carbon nanocomposite used as high-capacity anode materials of nextgeneration lithium-ion batteries.The nanocomposite had a unique structure of ultrafine...We demonstrate a facile route for the massive production of SnCb/carbon nanocomposite used as high-capacity anode materials of nextgeneration lithium-ion batteries.The nanocomposite had a unique structure of ultrafine SnO2 nanocrystals（5 nm,80 wt%） homogeneously dispersed in amorphous carbon matrix.This structure design can well accommodate the volume change of Li＋ insertion/desertion in SnO2,and prevent the aggregation of the nanosized active materials during cycling,leading to superior cycle performance with stable reversible capacity of 400 mAh/g at a high current rate of 3.3 A/g.展开更多
Compound Zn2Sn0.8Ti0.2O4 was synthesized by a hydrothermal method in which SnCl4-5H2O,TiCl4,ZnCl2 and N2H4-H2O were used as reactants.The composite Zn2Sn0.8Ti0.2O4/C was then prepared through a carbothermic reduction ...Compound Zn2Sn0.8Ti0.2O4 was synthesized by a hydrothermal method in which SnCl4-5H2O,TiCl4,ZnCl2 and N2H4-H2O were used as reactants.The composite Zn2Sn0.8Ti0.2O4/C was then prepared through a carbothermic reduction process using the as-prepared Zn2Sn0.8Ti0.2O4 and glucose as reactants.The structure,morphology and electrochemical properties of the as-prepared products were investigated by XRD,XPS,TEM and electrochemical measurements.In addition,electrochemical Li insertion/extraction in composite Zn2Sn0.8Ti0.2O4/C were examined by ex situ XRD and SEM.The first discharge capacity of Zn2SnO4 is about 1670.8 mA-h/g,with a capacity retain of 342.7 mA-h/g in the 40th cycle at a constant current density of 100 mA/g in the voltage range of 0.05-3.0 V.Comparing with the Zn2SnO4,some improved electrochemical properties are obtained for Zn2Sn0.8Ti0.2O4,Zn2SnO4/C and Zn2Sn0.8Ti0.2O4/C.The composite Zn2Sn0.8Ti0.2O4/C shows the best electrochemical properties,and its first discharge capacity is about 1530.0 mA-h/g,with a capacity retain of 479.1 mA-h/g the 100th cycle.展开更多
The Ti-Supported MnO_2 electrode was modified by introducing SnO_2+RuO_2+MnO_2 as an intermediate layer into the Ti/MnO_2 interface. The anodic polarization curves were measured at various temperatures ranging from 30...The Ti-Supported MnO_2 electrode was modified by introducing SnO_2+RuO_2+MnO_2 as an intermediate layer into the Ti/MnO_2 interface. The anodic polarization curves were measured at various temperatures ranging from 30 to 80℃ and the activation energy for the oxygen evolution reaction was evaluated. The experimental activation energy increased linearly with increasing the overpotential. The activation energy at the equilibrium potential was linearly correlated with the difference between the crystal field stabilization energies of Mn^(4+) at initial state and Mn^(4+) at transition state. The electrocatalysis characteristics of the anode were discussed by means of the mechanism of the substitution reaction of the ligand(S_N1 and S_N2) and molecular orbital theory. The results show that the anode has better electrocatalystic characteristics.展开更多
Increasing attention has been focused on potassium ion batteries(KIBs) as promising energy-sto rage system(ESS) owing to the abundance and low-cost of potassium resources.Here,SnS2/SnO2 hete rostructures were successf...Increasing attention has been focused on potassium ion batteries(KIBs) as promising energy-sto rage system(ESS) owing to the abundance and low-cost of potassium resources.Here,SnS2/SnO2 hete rostructures were successfully fixed onto stainless steel mesh(SnS2/SnO2/SSM) through a facile two-step hydrothermal method and used as anodes for KIBs.Due to the advantages of SnS2/SnO2 heterostructures and good conductivity of SSM substrate,the SnS2/SnO2/SSM anodes display enhanced electrochemical performance.The SnS2/SnO2/SSM anodes deliver specific capacity of 394 mA h g^-1 at 50 mA g^-1 over 100 cycles,better than SnO2/SSM.Even at 500 mA g^-1 after 250 cycles,high capacity of 155 mA h g^-1 can still be obtained.展开更多
SnO2@Co3O4 hollow nano-spheres have been prepared using the template-based sol-gel coating technique and their electrochemical performance as an anode for lithium-ion battery （LIB） was investigated. The size of synt...SnO2@Co3O4 hollow nano-spheres have been prepared using the template-based sol-gel coating technique and their electrochemical performance as an anode for lithium-ion battery （LIB） was investigated. The size of synthesized hollow spheres was about 50 nm with the shell thickness of 7-8 nm. The fabricated SnO2@Co3O4 hollow nano-sphere electrode exhibited an extraordinary reversible capacity （962 mAh-g-1 after 100 cycles at 100 mA-g-1）, good cyclability, and high rate capability, which was attributed to the Co-enhanced reversibility of the Li20 reduction reaction during cycling.展开更多
1 Results Recently,Ryoo's group reported the preparation of ordered mesoporous carbon using highly ordered mesoporous silica[1-2]. Mesoporous and nanowire SnO2 anode materials for lithium batteries were prepared u...1 Results Recently,Ryoo's group reported the preparation of ordered mesoporous carbon using highly ordered mesoporous silica[1-2]. Mesoporous and nanowire SnO2 anode materials for lithium batteries were prepared using KIT-6 and SBA-15 SiO2 templates. The as-prepared SnO2 nanowires had a diameter of 6 nm and a length of ≈3 μm and Brunauer-Emmett-Teller (BET) surface area of 80 m2/g while mesoporous SnO2 showed a pore size of 3.8 nm and a BET surface area of 160 m2/g. The charge capacities of these two an...展开更多
Cyclic voltammetry and chronopotentiometry have been used to study the Sb-doped Ti/SnO2 anodes prepared by magnetron sputtering. The results showed that magnetron sputtering condition influenced the surface morphology...Cyclic voltammetry and chronopotentiometry have been used to study the Sb-doped Ti/SnO2 anodes prepared by magnetron sputtering. The results showed that magnetron sputtering condition influenced the surface morphology and the properties of the anodes. After the Ti substrate was tempered in Ar at 600 ℃ for 1 h, Till1.5 on the surface generated from the acid etching was replaced by needle-like TiO2. The SnO2 coating on the above Ti substrate by magnetron sputtering with post-annealing was comprised of microrod and different with the traditional Ti/ SnO2 anode. The accelerated service life test showed that the microrod SnO2 anode gained the longest service time. The anode exhibited oscillations in the chronopotentiometry curves, and the microrod SnO2 coating almost dissolved after the life test. A model of layer-by-layer degradation mechanism for the anode was proposed.展开更多
This work was conducted to study the ability of anodic oxidation of azo dye C.I. Acid Red 73 （ART3） using the yttrium-doped Ti/SnO2-Sb electrodes. The effects of Sb doping level, yttrium doping level, thermal decomp...This work was conducted to study the ability of anodic oxidation of azo dye C.I. Acid Red 73 （ART3） using the yttrium-doped Ti/SnO2-Sb electrodes. The effects of Sb doping level, yttrium doping level, thermal decomposition temperature and cycle times of dip-coating thermal decomposition on the properties of the electrodes were investigated. The results showed that the excellent electrochemical activity of Ti/SnO2-Sb-Y electrode can be achieved at a 7：1 molar ratio of Sn：Sb and thermal decomposition temperature of 550~C. Moreover when the cycle times of dip-coating and thermal decomposition were up to 10 times, the performance of the electrode tends to be stable. The Ti/SnO2-Sb electrodes doped with yttrium （0.5 tool-%） showed the most excellent electrochemical activity. In addition, the influences of operating variables, including current density, initial pH, dye concentration and support electrolyte, on the colour removal, chemical oxygen demand （COD） removal and current efficiency were also investigated. Our results confirmed that the current efficiency increased with the concentrations of dye and sodium chloride. Moreover, increasing the current density and the initial pH would reduce the current efficiency.展开更多
基金Project(51404001)supported by the National Natural Science Foundation of ChinaProject([2014]1685)supported by the Scientific Research Foundation for the Returned Overseas Chinese Scholars,Ministry of Education,China
文摘A novel SnO2-based gas anode was developed for aluminum electrolysis in molten cryolite at 850 ＆#176;C to reduce energy consumption and decrease CO2 emissions. Hydrogen was introduced into the anode, participating in the anode reaction. Carbon and aluminum were used as the cathode and reference electrodes, respectively. Cyclic voltammetry was applied in the cell to investigate the electrochemical behavior of oxygen ion on platinum and SnO2-based materials. The potential for oxygen evolution on these electrode materials was determined. Then, galvanostatic electrolysis was performed on the gas anode, showing a significant depolarization effect （a decrease of ~0.8 V of the anode potential） after the introduction of hydrogen, compared with no gas introduction or the introduction of argon. The results indicate the involvement of hydrogen in the anode reaction （three-phase-boundary reaction including gas, electrolyte and electrode） and give the possibility for the utilization of reducing gas anodes for aluminum electrolysis.
基金supported by the National Natural Science Foundation of China(22075147 and 22179063)。
文摘Although metal oxide compounds are considered as desirable anode materials for potassium-ion batteries(PIBs)due to their high theoretical capacity,the large volume variation remains a key issue in realizing metal oxide anodes with long cycle life and excellent rate property.In this study,polypyrroleencapsulated Sb_(2)WO_(6)(denoted Sb_(2)WO_(6)@PPy)microflowers are synthesized by a one-step hydrothermal method followed by in-situ polymerization and coating by pyrrole.Leveraging the nanosheet-stacked Sb_(2)WO_(6)microflower structure,the improved electronic conductivity,and the architectural protection offered by the PPy coating,Sb_(2)WO_(6)@PPy exhibits boosted potassium storage properties,thereby demonstrating an outstanding rate property of 110.3 m A h g^(-1)at 5 A g^(-1)and delivering a long-period cycling stability with a reversible capacity of 197.2 m A h g^(-1)after 500 cycles at 1 A g^(-1).In addition,the conversion and alloying processes of Sb_(2)WO_(6)@PPy in PIBs with the generation of intermediates,K_(2)WO_(4)and K_(3)Sb,is determined by X-ray photoelectron spectroscopy,transmission electron microscopy,and exsitu X-ray diffraction during potassiation/depotassiation.Density functional theory calculations demonstrate that the robust coupling between PPy and Sb_(2)WO_(6)endues it with a much stronger total density of states and a built-in electric field,thereby increasing the electronic conductivity,and thus effectively reduces the K^(+)diffusion barrier.
基金supported by the National Natural Science Foundation of China (Grant No. 51302079)the National Natural Science Foundation of Hunan Province (Grant No. 2017JJ1008)
文摘It is urgent to solve the problems of the dramatic volume expansion and pulverization of SnO_2 anodes during cycling process in battery systems. To address this issue, we design a hybrid structure of N-doped carbon fibers@SnO_2 nanoflowers(NC@SnO_2) to overcome it in this work. The hybrid NC@SnO_2 is synthesized through the hydrothermal growth of SnO_2 nanoflowers on the surface of N-doped carbon fibers obtained by electrospinning. The NC is introduced not only to provide a support framework in guiding the growth of the SnO_2 nanoflowers and prevent the flower-like structures from agglomeration, but also serve as a conductive network to accelerate electronic transmission along one-dimensional structure effectively. When the hybrid NC@SnO_2 was served as anode, it exhibits a high discharge capacity of 750 Ah g^(-1) at 1 A g^(-1) after 100 cycles in Li-ion battery and 270 mAh g^(-1) at 100 mA g^(-1) for 100 cycles in Na-ion battery, respectively.
基金supported by the National Key Project on Basic Research(Grant No.2011CB935904)the National Natural Science Foundation of China(Grant No.21171163,91127020)NSF for Distinguished Young Scholars of Fujian Province(Grant No.2013J06006)
文摘A new SnO2-Fe2O3/SWCNTs（single-walled carbon nanotubes） ternary nanocomposite was first synthesized by a facile hydrothermal approach.SnO2 and Fe2O3 nanoparticles（NPs） were homogeneously located on the surface of SWCNTs,as confirmed by X-ray diffraction（XRD）,transmission electron microscope（TEM） and energy dispersive X-ray spectroscopy（EDX）.Due to the synergistic effect of different components,the as synthesized SnO2-Fe2O3/SWCNTs composite as an anode material for lithium-ion batteries exhibited excellent electrochemical performance with a high capacity of 692 mAh·g-1 which could be maintained after 50 cycles at 200 mA·g-1.Even at a high rate of2000 mA·g-1,the capacity was still remained at 656 mAh·g-1.
基金financially supported by the National Natural Science Foundation of China (No.20873046)the Specialized Research Fund for the Doctoral Program of HigherEducation (No.200805740004)Natural Science Foundation of Guangdong Province (No.10351063101000001)
文摘TiO2-coated SnO2 （TCS） hollow spheres, which are new anode materials for lithium ion （Li-ion） batteries, were prepared and characterized with X-ray diffraction （XRD）, scanning electron microscopy （SEM）, transmission electron microscopy （TEM）, cyclic voltammetry （CV）, and galvanostatic charge/discharge tests. The results obtained from XRD, SEM, and TEM show that TiO2 can be uniforrrdy coated on the surface of SnO2 hollow spheres with the assistance of anionic surfactant. The cyclic voltammograms indicate that both TiO2 and SnO2 exhibit the activity for Li-ion storage. The charge/discharge tests show that the prepared TCS hollow spheres have a higher reversible coulomb efficiency and a better cycling stability than the uncoated SnO2 hollow spheres.
基金supported by the National High-Tech Research and Development Program of China(Grant No. 280 2007AA05Z409)
文摘Stainless steel plates were successfully coated with SnO2-CeO2 films （SS/SnO2-CeO2） by brush coating with a solution of stannous chloride and cerium trichloride followed by thermal decomposition. It is proven that the properties of SnO2 films can be evidently improved by Ce doping, and 600℃ is the optimum temperature to prepare SS/SnO2-CeO2 anodes. The physicochemical and electrochemical properties as well as the elec- trocatalytic activity of the electrodes were investigated. It is found that the novel electrodes have compact microstructure, high overpotential for oxygen evolution （1.60 V vs SCE）, excellent electrochemical stability, relatively low cost and excellent catalytic activity for oxidizing pollutants. An industrial dye wastewater, which is hard to be purified by using conventional chemical flocculation methods, was oxidated by employing the SS/SnO2-CeO2 anodes, and 83.00% of color and 48.62% of chemical oxygen demand （COD） removal was achieved under the cell voltage of 5 V within only 2 min, and the electricity consumption is only 1.83 kWh for oxidizing I m3 of dye wastewater.
基金Project supported by the National Key Basic Research Program of China (Grant No 2007CB310500)the Chinese Ministry of Education (Grant No 705040)the National Natural Science Foundation of China (Grant Nos 90606009, 60571044 and 10774174)
文摘Well-dispersed SnO2 nanorods with diameter of 4-15 nm and length of 100-200 nm are synthesised through a hydrothermal route and their potential as anode materials in lithium-ion batteries is investigated. The observed initial discharge capacity is as high as 1778 mA.h/g, much higher than the theoretical value of the bulk SnO2 （1494 mA.h/g）. During the following 15 cycles, the reversible capacity decreases from 929 to 576 mA-h/g with a fading rate of 3.5% per cycle. The fading mechanism is discussed. Serious capacity fading can be avoided by reducing the cycling voltages from 0.05-3.0 to 0.4-1.2 V. At the end, SnO2 nanorods with much smaller size are synthesized and their performance as anode materials is studied. The size effect on the electrochemical properties is briefly discussed.
基金supported by the National Science Foundation of China(Grant No.51201065 and No.51231003)the Natural Science Foundation of Guangdong Province(S2012040008050)the Doctorate Foundation of Ministry of Education(Grant No.20120172120007 and No.2014ZZ0002)
文摘We demonstrate a facile route for the massive production of SnCb/carbon nanocomposite used as high-capacity anode materials of nextgeneration lithium-ion batteries.The nanocomposite had a unique structure of ultrafine SnO2 nanocrystals（5 nm,80 wt%） homogeneously dispersed in amorphous carbon matrix.This structure design can well accommodate the volume change of Li＋ insertion/desertion in SnO2,and prevent the aggregation of the nanosized active materials during cycling,leading to superior cycle performance with stable reversible capacity of 400 mAh/g at a high current rate of 3.3 A/g.
基金Project (51004028) supported by the National Natural Science Foundation of China
文摘Compound Zn2Sn0.8Ti0.2O4 was synthesized by a hydrothermal method in which SnCl4-5H2O,TiCl4,ZnCl2 and N2H4-H2O were used as reactants.The composite Zn2Sn0.8Ti0.2O4/C was then prepared through a carbothermic reduction process using the as-prepared Zn2Sn0.8Ti0.2O4 and glucose as reactants.The structure,morphology and electrochemical properties of the as-prepared products were investigated by XRD,XPS,TEM and electrochemical measurements.In addition,electrochemical Li insertion/extraction in composite Zn2Sn0.8Ti0.2O4/C were examined by ex situ XRD and SEM.The first discharge capacity of Zn2SnO4 is about 1670.8 mA-h/g,with a capacity retain of 342.7 mA-h/g in the 40th cycle at a constant current density of 100 mA/g in the voltage range of 0.05-3.0 V.Comparing with the Zn2SnO4,some improved electrochemical properties are obtained for Zn2Sn0.8Ti0.2O4,Zn2SnO4/C and Zn2Sn0.8Ti0.2O4/C.The composite Zn2Sn0.8Ti0.2O4/C shows the best electrochemical properties,and its first discharge capacity is about 1530.0 mA-h/g,with a capacity retain of 479.1 mA-h/g the 100th cycle.
基金Supported by the National Natural Science Foundation of China.
文摘The Ti-Supported MnO_2 electrode was modified by introducing SnO_2+RuO_2+MnO_2 as an intermediate layer into the Ti/MnO_2 interface. The anodic polarization curves were measured at various temperatures ranging from 30 to 80℃ and the activation energy for the oxygen evolution reaction was evaluated. The experimental activation energy increased linearly with increasing the overpotential. The activation energy at the equilibrium potential was linearly correlated with the difference between the crystal field stabilization energies of Mn^(4+) at initial state and Mn^(4+) at transition state. The electrocatalysis characteristics of the anode were discussed by means of the mechanism of the substitution reaction of the ligand(S_N1 and S_N2) and molecular orbital theory. The results show that the anode has better electrocatalystic characteristics.
基金This work was financially supported by the National Natural Science Foundation of China(Nos.51704188,51464020,5170219961705125 and 51802181)the research starting foundation from Shaanxi University of Science and Technology(No.2018GBJ-04)。
文摘Increasing attention has been focused on potassium ion batteries(KIBs) as promising energy-sto rage system(ESS) owing to the abundance and low-cost of potassium resources.Here,SnS2/SnO2 hete rostructures were successfully fixed onto stainless steel mesh(SnS2/SnO2/SSM) through a facile two-step hydrothermal method and used as anodes for KIBs.Due to the advantages of SnS2/SnO2 heterostructures and good conductivity of SSM substrate,the SnS2/SnO2/SSM anodes display enhanced electrochemical performance.The SnS2/SnO2/SSM anodes deliver specific capacity of 394 mA h g^-1 at 50 mA g^-1 over 100 cycles,better than SnO2/SSM.Even at 500 mA g^-1 after 250 cycles,high capacity of 155 mA h g^-1 can still be obtained.
文摘SnO2@Co3O4 hollow nano-spheres have been prepared using the template-based sol-gel coating technique and their electrochemical performance as an anode for lithium-ion battery （LIB） was investigated. The size of synthesized hollow spheres was about 50 nm with the shell thickness of 7-8 nm. The fabricated SnO2@Co3O4 hollow nano-sphere electrode exhibited an extraordinary reversible capacity （962 mAh-g-1 after 100 cycles at 100 mA-g-1）, good cyclability, and high rate capability, which was attributed to the Co-enhanced reversibility of the Li20 reduction reaction during cycling.
文摘1 Results Recently,Ryoo's group reported the preparation of ordered mesoporous carbon using highly ordered mesoporous silica[1-2]. Mesoporous and nanowire SnO2 anode materials for lithium batteries were prepared using KIT-6 and SBA-15 SiO2 templates. The as-prepared SnO2 nanowires had a diameter of 6 nm and a length of ≈3 μm and Brunauer-Emmett-Teller (BET) surface area of 80 m2/g while mesoporous SnO2 showed a pore size of 3.8 nm and a BET surface area of 160 m2/g. The charge capacities of these two an...
文摘Cyclic voltammetry and chronopotentiometry have been used to study the Sb-doped Ti/SnO2 anodes prepared by magnetron sputtering. The results showed that magnetron sputtering condition influenced the surface morphology and the properties of the anodes. After the Ti substrate was tempered in Ar at 600 ℃ for 1 h, Till1.5 on the surface generated from the acid etching was replaced by needle-like TiO2. The SnO2 coating on the above Ti substrate by magnetron sputtering with post-annealing was comprised of microrod and different with the traditional Ti/ SnO2 anode. The accelerated service life test showed that the microrod SnO2 anode gained the longest service time. The anode exhibited oscillations in the chronopotentiometry curves, and the microrod SnO2 coating almost dissolved after the life test. A model of layer-by-layer degradation mechanism for the anode was proposed.
基金The authors are grateful for the financial support from the National Natural Science Foundation of China （Grant No. 21276177）, and the Natural Science Foundation of Tianjin （Grant No. 10JCYBJC04900）.
文摘This work was conducted to study the ability of anodic oxidation of azo dye C.I. Acid Red 73 （ART3） using the yttrium-doped Ti/SnO2-Sb electrodes. The effects of Sb doping level, yttrium doping level, thermal decomposition temperature and cycle times of dip-coating thermal decomposition on the properties of the electrodes were investigated. The results showed that the excellent electrochemical activity of Ti/SnO2-Sb-Y electrode can be achieved at a 7：1 molar ratio of Sn：Sb and thermal decomposition temperature of 550~C. Moreover when the cycle times of dip-coating and thermal decomposition were up to 10 times, the performance of the electrode tends to be stable. The Ti/SnO2-Sb electrodes doped with yttrium （0.5 tool-%） showed the most excellent electrochemical activity. In addition, the influences of operating variables, including current density, initial pH, dye concentration and support electrolyte, on the colour removal, chemical oxygen demand （COD） removal and current efficiency were also investigated. Our results confirmed that the current efficiency increased with the concentrations of dye and sodium chloride. Moreover, increasing the current density and the initial pH would reduce the current efficiency.
