Nickel-manganese binary layered oxides with high working potential and low cost are potential candidates for sodium-ion batteries,but their electrochemical properties are highly related to compositional diversity.Dive...Nickel-manganese binary layered oxides with high working potential and low cost are potential candidates for sodium-ion batteries,but their electrochemical properties are highly related to compositional diversity.Diverse composite materials with various phase structures of P3,P2/P3,P2,P2/O3,and P2/P3/O3 were synthesized by manipulating the sodium content and calcination conditions,leading to the construction of a synthetic phase diagram for Na_(x)Ni_(0.25)Mn_(0.75)O_(2)(0.45≤x≤1.1).Then,we compared the electrochemical characteristics and structural evolution during the desodiation/sodiation process of P2,P2/P3,P2/03,and P2/P3/O3-Na_(x)Ni_(0.25)Mn_(0.75)O_(2).Among them,P2/P3-Na0.75Ni0.25Mn0.75O2exhibits the best rate capability of 90.9 mA h g^(-1)at 5 C,with an initial discharge capacity of 142.62 mA h g^(-1)at 0.1 C and a capacity retention rate of 78.25%after 100 cycles at 1 C in the voltage range of 2-4.3 V.The observed superior sodium storage performance of P2/P3 hybrids compared to other composite phases can be attributed to the enhanced Na^(+)transfer dynamic,reduction of the Jahn-teller effect,and improved reaction reversibility induced by the synergistic effect of P2 and P3 phases.The systematic research and exploration of phases in Na_(x)Ni_(0.25)Mn_(0.75)O_(2)provide new sights into high-performance nickel-manganese binary layered oxide for sodium-ion batteries.展开更多
Poly(3,4-ethylenedioxyethiophene)-polystyrene sulfonic acid(PEDOT:PSS)/polyallyl dimethyl ammonium chloride modified reduced graphene oxide(PDDA-rGO)was layer by layer self-assembled on the cotton fiber.The surface mo...Poly(3,4-ethylenedioxyethiophene)-polystyrene sulfonic acid(PEDOT:PSS)/polyallyl dimethyl ammonium chloride modified reduced graphene oxide(PDDA-rGO)was layer by layer self-assembled on the cotton fiber.The surface morphology and electric property was investigated.The results confirmed the dense membrane of PEDOT:PSS and the lamellar structure of PDDA-rGO on the fibers.It has excellent electrical conductivity and mechanical properties.The fiber based electrochemical transistor(FECTs)prepared by the composite conductive fiber has a maximum output current of 8.7 mA,a transconductance peak of 10 mS,an on time of 1.37 s,an off time of 1.6 s and excellent switching stability.Most importantly,the devices by layer by layer self-assembly technology opens a path for the true integration of organic electronics with traditional textile technologies and materials,laying the foundation for their later widespread application.展开更多
The kinetics of the interaction of MnO2, Mn2O3, and Mn3O4, with sulphuric acid solutions and the effect of oxalic acid on this process are studied. As the sulphuric acid concentration is increased from 0.1 to 5 N, the...The kinetics of the interaction of MnO2, Mn2O3, and Mn3O4, with sulphuric acid solutions and the effect of oxalic acid on this process are studied. As the sulphuric acid concentration is increased from 0.1 to 5 N, the dissolution rate of Mn2O3, Mn3O4 to MnO2 and Mn2+ ions decreases, whereas it increases with the concentration of Mn2+ ions. Upon the addition of H2Ox, the complete dissolution of Mn3O4 occurs more quickly. The reaction order with respect to the H+ and O x2- ions is +0.5 ± 0.1. A mechanism of MnO2 dissolution promotion by?O x2- is proposed. The dissolution rate was found to depend on the concentrations of?MnHOx - ions and was highest at pH 1.6 ± 0.2. A rate law and mechanism are suggested for manganese oxides dissolution.展开更多
Recently,sodium-ion batteries(SIBs),regarded as promising supplements for lithium-ion batteries(LIBs),especially in the large-scale energy storage field,are attracting more and more attention.However,the limited suita...Recently,sodium-ion batteries(SIBs),regarded as promising supplements for lithium-ion batteries(LIBs),especially in the large-scale energy storage field,are attracting more and more attention.However,the limited suitable cathode materials hinder the wide commercialization of SIBs.Given this aspect,in this work,a new layered oxide with 4d metal Tin was synthesized and investigated as cathode material for SIBs.Two optimized sodium-deficient O3-Na_(0.9)Ni_(0.45)Sn_(0.55)O_2and O3-Na_(0.9)Ni_(0.4)Mn_(0.1)Sn_(0.5)O_2were selected for comprehensive investigation,both of which exhibited high operating voltage of around 3.45 V with smooth charge/discharge curves.In comparison,O3-Na_(0.9)Ni_(0.4)Mn_(0.1)Sn_(0.5)O_2shows a higher reversible capacity(65 m A h/g,0.1 C),better rate capability and cycling stability than that of O3-Na_(0.9)Ni_(0.45)Sn_(0.55)O_2(50 mA h/g,0.1 C),indicating that a small amount of Mn-substitution can improve the electrochemical performance.This work presents a new possibility of discovering potential cathode candidates by exploring the Tin-based layered oxides.展开更多
The mixed oxides, including LaBa\-2Cu\-3O\-7, LaBaCu\-2O\-5, La\-4BaCu\-5O 12 with perovskite structure, were prepared. The catalysts were characterized by means of chemical analysis, XRD, H\-2_TPR. It was found that ...The mixed oxides, including LaBa\-2Cu\-3O\-7, LaBaCu\-2O\-5, La\-4BaCu\-5O 12 with perovskite structure, were prepared. The catalysts were characterized by means of chemical analysis, XRD, H\-2_TPR. It was found that their structures were layered ABO\-3 perovskite structure and they were the active catalysts for the NO reduction by CO. The existance of Cu 3+ is an important factor to give the catalysts a high activity for the NO reduction by CO.展开更多
基金supported by project from the National Natural Science Foundation of China(21805018)by the Sichuan Science and Technology Program(2022ZHCG0018,2023NSFSC0117,2023ZHCG0060)+1 种基金the Yibin Science and Technology Program(2022JB005)project funded by the China Postdoctoral Science Foundation(2022M722704)。
文摘Nickel-manganese binary layered oxides with high working potential and low cost are potential candidates for sodium-ion batteries,but their electrochemical properties are highly related to compositional diversity.Diverse composite materials with various phase structures of P3,P2/P3,P2,P2/O3,and P2/P3/O3 were synthesized by manipulating the sodium content and calcination conditions,leading to the construction of a synthetic phase diagram for Na_(x)Ni_(0.25)Mn_(0.75)O_(2)(0.45≤x≤1.1).Then,we compared the electrochemical characteristics and structural evolution during the desodiation/sodiation process of P2,P2/P3,P2/03,and P2/P3/O3-Na_(x)Ni_(0.25)Mn_(0.75)O_(2).Among them,P2/P3-Na0.75Ni0.25Mn0.75O2exhibits the best rate capability of 90.9 mA h g^(-1)at 5 C,with an initial discharge capacity of 142.62 mA h g^(-1)at 0.1 C and a capacity retention rate of 78.25%after 100 cycles at 1 C in the voltage range of 2-4.3 V.The observed superior sodium storage performance of P2/P3 hybrids compared to other composite phases can be attributed to the enhanced Na^(+)transfer dynamic,reduction of the Jahn-teller effect,and improved reaction reversibility induced by the synergistic effect of P2 and P3 phases.The systematic research and exploration of phases in Na_(x)Ni_(0.25)Mn_(0.75)O_(2)provide new sights into high-performance nickel-manganese binary layered oxide for sodium-ion batteries.
基金Funded by the Key R&D Program of the Science and Technology Department of Hubei Province(No.2022BCE008)。
文摘Poly(3,4-ethylenedioxyethiophene)-polystyrene sulfonic acid(PEDOT:PSS)/polyallyl dimethyl ammonium chloride modified reduced graphene oxide(PDDA-rGO)was layer by layer self-assembled on the cotton fiber.The surface morphology and electric property was investigated.The results confirmed the dense membrane of PEDOT:PSS and the lamellar structure of PDDA-rGO on the fibers.It has excellent electrical conductivity and mechanical properties.The fiber based electrochemical transistor(FECTs)prepared by the composite conductive fiber has a maximum output current of 8.7 mA,a transconductance peak of 10 mS,an on time of 1.37 s,an off time of 1.6 s and excellent switching stability.Most importantly,the devices by layer by layer self-assembly technology opens a path for the true integration of organic electronics with traditional textile technologies and materials,laying the foundation for their later widespread application.
文摘The kinetics of the interaction of MnO2, Mn2O3, and Mn3O4, with sulphuric acid solutions and the effect of oxalic acid on this process are studied. As the sulphuric acid concentration is increased from 0.1 to 5 N, the dissolution rate of Mn2O3, Mn3O4 to MnO2 and Mn2+ ions decreases, whereas it increases with the concentration of Mn2+ ions. Upon the addition of H2Ox, the complete dissolution of Mn3O4 occurs more quickly. The reaction order with respect to the H+ and O x2- ions is +0.5 ± 0.1. A mechanism of MnO2 dissolution promotion by?O x2- is proposed. The dissolution rate was found to depend on the concentrations of?MnHOx - ions and was highest at pH 1.6 ± 0.2. A rate law and mechanism are suggested for manganese oxides dissolution.
基金supported by funding from the Science and Technology Project of the State Grid Corporation of China ("research on key technology of low-strain layered oxides for long-life sodium-ion batteries", DG71-16-027)
文摘Recently,sodium-ion batteries(SIBs),regarded as promising supplements for lithium-ion batteries(LIBs),especially in the large-scale energy storage field,are attracting more and more attention.However,the limited suitable cathode materials hinder the wide commercialization of SIBs.Given this aspect,in this work,a new layered oxide with 4d metal Tin was synthesized and investigated as cathode material for SIBs.Two optimized sodium-deficient O3-Na_(0.9)Ni_(0.45)Sn_(0.55)O_2and O3-Na_(0.9)Ni_(0.4)Mn_(0.1)Sn_(0.5)O_2were selected for comprehensive investigation,both of which exhibited high operating voltage of around 3.45 V with smooth charge/discharge curves.In comparison,O3-Na_(0.9)Ni_(0.4)Mn_(0.1)Sn_(0.5)O_2shows a higher reversible capacity(65 m A h/g,0.1 C),better rate capability and cycling stability than that of O3-Na_(0.9)Ni_(0.45)Sn_(0.55)O_2(50 mA h/g,0.1 C),indicating that a small amount of Mn-substitution can improve the electrochemical performance.This work presents a new possibility of discovering potential cathode candidates by exploring the Tin-based layered oxides.
文摘The mixed oxides, including LaBa\-2Cu\-3O\-7, LaBaCu\-2O\-5, La\-4BaCu\-5O 12 with perovskite structure, were prepared. The catalysts were characterized by means of chemical analysis, XRD, H\-2_TPR. It was found that their structures were layered ABO\-3 perovskite structure and they were the active catalysts for the NO reduction by CO. The existance of Cu 3+ is an important factor to give the catalysts a high activity for the NO reduction by CO.
