Developing high-performance anode materials is crucial for the advancement of sodium-ion capacitors with high-energy density and large power density.Bimetallic oxides exhibit a high specific capacity due to their syne...Developing high-performance anode materials is crucial for the advancement of sodium-ion capacitors with high-energy density and large power density.Bimetallic oxides exhibit a high specific capacity due to their synergistic effects in electrochemical processes.However,challenges such as poor electrical conductivity,slow ion transport,and volume expansion severely limit their development.In this study,Co_(2)VO_(4)@C-1.5 was synthesized through a straightforward method involving solvent-heating and carbonization via calcination.The synergistic effect of Co and V,mitigation of volume expansion by the carbon-coated layer,enhancement of pseudocapacitive behavior and improved electrical conductivity of Co_(2)VO_(4)@C-1.5 contribute to its superior electrochemical performance.The specific capacity of Co_(2)VO_(4)@C-1.5 remained steady at 288.8 and 171.7 mAh g^(-1)after 100 and 500 cycles at 100 and 1000 mA g^(-1),respectively.Density functional theory(DFT)calculations show a notable reduction in the energy barrier of Co_(2)VO_(4)@C-1.5.Furthermore,the assembled sodium-ion capacitor Co_(2)VO_(4)@C-1.5//AC demonstrates high-energy density(108.5 Wh kg^(-1)at 99.8 W kg^(-1)),remarkable power density(38.2 Wh kg^(-1)at 12,000 W kg^(-1)),and longcycle stability(capacity retention of 80.6%after 6000 cycles).The design and optimization of the carbon-coated structure provide valuable insights for the development of bimetallic oxide materials in sodium-ion capacitors(SICs).展开更多
The insulating nature and dissolution of vanadium-based oxides in aqueous electrolytes result in low capacity and lifespan during charge/discharge process, which is unable to meet the demands for the development and a...The insulating nature and dissolution of vanadium-based oxides in aqueous electrolytes result in low capacity and lifespan during charge/discharge process, which is unable to meet the demands for the development and application of high-energy-density aqueous zinc-ion batteries(AZIBs). Herein, a novel V_(2)O_(5-x)@C composite cathode consisting of conductive carbon coatings with abundant oxygen vacancies is specifically designed through plasma-enhanced chemical vapor deposition(PECVD) method. As expected,the ideal microstructure of V_(2)O_(5-x)@C cathode enables large specific surface areas, fast electron/ion diffusion kinetics, and superior interfacial stability, which can realize outstanding cycling stability and electrochemical performance. Consequently, the V_(2)O_(5-x)@C composite cathode delivers a high reversible rate capacity of 130.6 mAh/g at 10 A/g and remains 277.6 mAh/g when returned to 1 A/g. In addition, the Zn//V_(2)O_(5-x)@C full cell can stably cycle for 1000 cycles with a high initial specific capacity of 149.2 m Ah/g,possessing 83.8% capacity retention at 5 A/g. The process of constructing a conductive layer on the surface of cathode materials while increasing oxygen vacancies in the structure through PECVD provides new insight into the design of high-performance cathode materials for AZIBs.展开更多
Na_(3)V_(2)(PO_(4))_(3)is a very prospective sodium-ion batteries(SIBs)electrode material owing to its NASICON structure and high reversible capacity.Conversely,on account of its intrinsic poor electronic conductivity...Na_(3)V_(2)(PO_(4))_(3)is a very prospective sodium-ion batteries(SIBs)electrode material owing to its NASICON structure and high reversible capacity.Conversely,on account of its intrinsic poor electronic conductivity,Na_(3)V_(2)(PO_(4))_(3)electrode materials confront with some significant limitations like poor cycle and rate performance which inhibit their practical applications in the energy fields.Herein,a simple two-step method has been implemented for the successful preparation of carbon-coated Na_(3)V_(2)(PO_(4))_(3)materials.As synthesized sample shows a remarkable electrochemical performance of 124.1 mAh/g at 0.1 C(1 C=117.6 mA/g),retaining 78.5 mAh/g under a high rate of 200 C and a long cycle-performance(retaining 80.7 mAh/g even after 10000 cycles at 20 C),outperforming the most advanced cathode materials as reported in literatures.展开更多
A novel nano-SnO2/graphite electrode has been prepared via polishing procedure to produce active and stable surface. The modified electrode resolves the overlapping voltammetric response of dopamine and ascorbic acid...A novel nano-SnO2/graphite electrode has been prepared via polishing procedure to produce active and stable surface. The modified electrode resolves the overlapping voltammetric response of dopamine and ascorbic acid into two well-defined peaks by 230 mV. The mechanism of discrimination of dopamine from ascorbic acid is discussed. Dopamine and ascorbic acid can be determined simultaneously with the modified electrode. The electrode shows good sensitivity, selectivity and stability.展开更多
The chemical composition of the passivating layer formed on nano SnO2 anodes in 1 M LiClO4＋ （ethylene carbonate）EC ＋ （dimethyl carbonate）DMC at different charge/discharge states in lithium secondary batteries wa...The chemical composition of the passivating layer formed on nano SnO2 anodes in 1 M LiClO4＋ （ethylene carbonate）EC ＋ （dimethyl carbonate）DMC at different charge/discharge states in lithium secondary batteries was studied using extra reflectance FTIR spectra. Results show that solvent decomposition reaction that generally occurs on the surface of carbon and alkali metal electrodes also takes place on nano-SnO2 anode, and the major constituent of the passivating layer is Li2CO3 and ROCO2Li. Formation of the passivating layer would certainly lead to the irreversible capacity loss.展开更多
The dependence of the microstructural change and lattice space symmetry of nano-SnO2 on the annealing temperature has been studied systematically using Raman spectroscopy and X-ray diffraction.Comparing the results of...The dependence of the microstructural change and lattice space symmetry of nano-SnO2 on the annealing temperature has been studied systematically using Raman spectroscopy and X-ray diffraction.Comparing the results of nano-SnO2 with the results of amorphous film and single crystal of SnO2 it is found that the new Raman peaks N1 and N2 are in accordance with Matossi’s force constant model completely.When the annealing temperature is near 673K,the local lattice disorders and the density of vacant lattice decrease rapidly in the nano-SnO2 grains.The lattice distortion and the new Raman peaks disappear almost at the same time.The possible mechanisms of the microstructural change and the new Raman peaks NI and N2 are discussed.展开更多
基金financially supported by the Applied Basic Research Project of Qinghai Province(No.2024-ZJ-766)the Youth Innovation Promotion Association CAS(No.2018466)
文摘Developing high-performance anode materials is crucial for the advancement of sodium-ion capacitors with high-energy density and large power density.Bimetallic oxides exhibit a high specific capacity due to their synergistic effects in electrochemical processes.However,challenges such as poor electrical conductivity,slow ion transport,and volume expansion severely limit their development.In this study,Co_(2)VO_(4)@C-1.5 was synthesized through a straightforward method involving solvent-heating and carbonization via calcination.The synergistic effect of Co and V,mitigation of volume expansion by the carbon-coated layer,enhancement of pseudocapacitive behavior and improved electrical conductivity of Co_(2)VO_(4)@C-1.5 contribute to its superior electrochemical performance.The specific capacity of Co_(2)VO_(4)@C-1.5 remained steady at 288.8 and 171.7 mAh g^(-1)after 100 and 500 cycles at 100 and 1000 mA g^(-1),respectively.Density functional theory(DFT)calculations show a notable reduction in the energy barrier of Co_(2)VO_(4)@C-1.5.Furthermore,the assembled sodium-ion capacitor Co_(2)VO_(4)@C-1.5//AC demonstrates high-energy density(108.5 Wh kg^(-1)at 99.8 W kg^(-1)),remarkable power density(38.2 Wh kg^(-1)at 12,000 W kg^(-1)),and longcycle stability(capacity retention of 80.6%after 6000 cycles).The design and optimization of the carbon-coated structure provide valuable insights for the development of bimetallic oxide materials in sodium-ion capacitors(SICs).
基金financially supported by the National Natural Science Foundation of China (No. 52377222)Natural Science Foundation of Hunan Province (No. 2023JJ20064)。
文摘The insulating nature and dissolution of vanadium-based oxides in aqueous electrolytes result in low capacity and lifespan during charge/discharge process, which is unable to meet the demands for the development and application of high-energy-density aqueous zinc-ion batteries(AZIBs). Herein, a novel V_(2)O_(5-x)@C composite cathode consisting of conductive carbon coatings with abundant oxygen vacancies is specifically designed through plasma-enhanced chemical vapor deposition(PECVD) method. As expected,the ideal microstructure of V_(2)O_(5-x)@C cathode enables large specific surface areas, fast electron/ion diffusion kinetics, and superior interfacial stability, which can realize outstanding cycling stability and electrochemical performance. Consequently, the V_(2)O_(5-x)@C composite cathode delivers a high reversible rate capacity of 130.6 mAh/g at 10 A/g and remains 277.6 mAh/g when returned to 1 A/g. In addition, the Zn//V_(2)O_(5-x)@C full cell can stably cycle for 1000 cycles with a high initial specific capacity of 149.2 m Ah/g,possessing 83.8% capacity retention at 5 A/g. The process of constructing a conductive layer on the surface of cathode materials while increasing oxygen vacancies in the structure through PECVD provides new insight into the design of high-performance cathode materials for AZIBs.
基金the financial supports from the National Natural Science Foundation of China(No.51774251)Shanghai Science and Technology Commission's"2020 Science and Technology Innovation Action Plan"(No.20511104003)+3 种基金Hebei Natural Science Foundation for Distinguished Young Scholars(No.B2017203313)Hundred Excellent Innovative Talents Support Program in Hebei Province(No.SLRC2017057)Talent Engineering Training Funds of Hebei Province(No.A201802001)the Opening Project of the State Key Laboratory of Advanced Chemical Power Sources(No.SKL-ACPS-C-11).
文摘Na_(3)V_(2)(PO_(4))_(3)is a very prospective sodium-ion batteries(SIBs)electrode material owing to its NASICON structure and high reversible capacity.Conversely,on account of its intrinsic poor electronic conductivity,Na_(3)V_(2)(PO_(4))_(3)electrode materials confront with some significant limitations like poor cycle and rate performance which inhibit their practical applications in the energy fields.Herein,a simple two-step method has been implemented for the successful preparation of carbon-coated Na_(3)V_(2)(PO_(4))_(3)materials.As synthesized sample shows a remarkable electrochemical performance of 124.1 mAh/g at 0.1 C(1 C=117.6 mA/g),retaining 78.5 mAh/g under a high rate of 200 C and a long cycle-performance(retaining 80.7 mAh/g even after 10000 cycles at 20 C),outperforming the most advanced cathode materials as reported in literatures.
文摘A novel nano-SnO2/graphite electrode has been prepared via polishing procedure to produce active and stable surface. The modified electrode resolves the overlapping voltammetric response of dopamine and ascorbic acid into two well-defined peaks by 230 mV. The mechanism of discrimination of dopamine from ascorbic acid is discussed. Dopamine and ascorbic acid can be determined simultaneously with the modified electrode. The electrode shows good sensitivity, selectivity and stability.
基金the Natural Science Foundation of Hubei Provine (No.2007ABA320)National 973 Key Program
文摘The chemical composition of the passivating layer formed on nano SnO2 anodes in 1 M LiClO4＋ （ethylene carbonate）EC ＋ （dimethyl carbonate）DMC at different charge/discharge states in lithium secondary batteries was studied using extra reflectance FTIR spectra. Results show that solvent decomposition reaction that generally occurs on the surface of carbon and alkali metal electrodes also takes place on nano-SnO2 anode, and the major constituent of the passivating layer is Li2CO3 and ROCO2Li. Formation of the passivating layer would certainly lead to the irreversible capacity loss.
基金Project supported by the Foundation of State Science and Technology and the Natural Science Foundation of Anhui Province.
文摘The dependence of the microstructural change and lattice space symmetry of nano-SnO2 on the annealing temperature has been studied systematically using Raman spectroscopy and X-ray diffraction.Comparing the results of nano-SnO2 with the results of amorphous film and single crystal of SnO2 it is found that the new Raman peaks N1 and N2 are in accordance with Matossi’s force constant model completely.When the annealing temperature is near 673K,the local lattice disorders and the density of vacant lattice decrease rapidly in the nano-SnO2 grains.The lattice distortion and the new Raman peaks disappear almost at the same time.The possible mechanisms of the microstructural change and the new Raman peaks NI and N2 are discussed.
