The vertical sections of the La−Fe−B system were investigated using electron probe microanalysis and differential thermal analysis.Based on the microstructures and phase compositions of the as-cast and equilibrium all...The vertical sections of the La−Fe−B system were investigated using electron probe microanalysis and differential thermal analysis.Based on the microstructures and phase compositions of the as-cast and equilibrium alloys,together with their heat flow−temperature curves,phase diagrams for three vertical sections were drawn:La_(x)Fe_(82)B_(y)(x+y=18),La_(x)Fe_(70)B_(y)(x+y=30)and La_(x)Fe_(53)B_(y)(x+y=47),where x and y represent mass fraction of La and B,respectively,%.Additionally,according to the phase diagrams,the compound La2Fe14B was identified as a stable phase at high temperatures.It was found to be stable between 926.2 and 792.6℃;at low temperatures,however,it decomposed into α-La,α-Fe and LaFe_(4)B_(4),according to the reaction La_(2)Fe_(14)B→α-Fe+α-La+LaFe_(4)B_(4).展开更多
As a promising anode for sodium-ion batteries(SIBs),the performance of SnO_(2) is still limited by inferior electronic conductivity and large volume change.To address this issue,herein,the intergrowth structured SnO_(...As a promising anode for sodium-ion batteries(SIBs),the performance of SnO_(2) is still limited by inferior electronic conductivity and large volume change.To address this issue,herein,the intergrowth structured SnO_(2)/CoSn_(2)@C nanocomposite has been fabricated by a two-step process combining hydrothermal synthesis with carbon coating.展开更多
La_(1-x)Mg_(x)Ni_(2.8)Co_(0.4)Mn_(0.1)Al_(0.2)(x=0.25,0.30,0.33)alloys were prepared by induction melting followed by annealing treatments(1,073 K)for 10 h.The structure and electrochemical properties of La_(1-x)Mg_(x...La_(1-x)Mg_(x)Ni_(2.8)Co_(0.4)Mn_(0.1)Al_(0.2)(x=0.25,0.30,0.33)alloys were prepared by induction melting followed by annealing treatments(1,073 K)for 10 h.The structure and electrochemical properties of La_(1-x)Mg_(x)Ni_(2.8)Co_(0.4)Mn_(0.1)Al_(0.2)(x=0.25,0.30,0.33)hydrogen storage alloys were investigated by X-ray powder diffraction(XRD)and electrochemical measurement methods.XRD results reveal that all the alloys mainly consist of LaNi5 phase and La2 Ni7 phase.The electrochemical experiments demonstrate that the substitution of Mg for La can increase the maximum discharge capacity and improve the high-rate dischargeability of the alloy electrodes.The high-rate dischargeability of alloy electrodes increases from 39.4%to63.1%with x increasing from 0.25 to 0.33 at discharge current density of 1,500 mA·g^(-1).However,the addition of Mg reduces the cycling stability of the electrodes.Furthermore,the results obtained from the electrochemical impedance spectroscopy and linear polarization measurements show that the hydriding kinetics on the hydrogen storage alloys are controlled by charge-transfer step.展开更多
基金financially supported by the Natural Science Foundation of China(No.51761007)the Guangxi Natural Science Foundation,China(Nos.2019GXNSFAA245003,2018GXNSFAA294069,2020GXNSFFA297004,2021GXNSFDA075009)+5 种基金the Guangxi Project of Science and Technology,China(Nos.AD19110078,AA18242023-1)the Scientific Research Foundation of Guilin University of Electronic Technology,China(No.UF18016)the Guangxi Key Laboratory of Processing for Non-ferrous Metals and Featured Materials(No.2019GXYSOF08),Chinathe Guangxi Key Laboratory of Information Materials,China(No.191012-Z)the National Key R&D Program of China(No.2016YFB0700901)financial support from the foundation for Guangxi Bagui scholars,China。
文摘The vertical sections of the La−Fe−B system were investigated using electron probe microanalysis and differential thermal analysis.Based on the microstructures and phase compositions of the as-cast and equilibrium alloys,together with their heat flow−temperature curves,phase diagrams for three vertical sections were drawn:La_(x)Fe_(82)B_(y)(x+y=18),La_(x)Fe_(70)B_(y)(x+y=30)and La_(x)Fe_(53)B_(y)(x+y=47),where x and y represent mass fraction of La and B,respectively,%.Additionally,according to the phase diagrams,the compound La2Fe14B was identified as a stable phase at high temperatures.It was found to be stable between 926.2 and 792.6℃;at low temperatures,however,it decomposed into α-La,α-Fe and LaFe_(4)B_(4),according to the reaction La_(2)Fe_(14)B→α-Fe+α-La+LaFe_(4)B_(4).
基金the Natural Science Foundation of Guangxi Province,China(Nos.2019GXNSFDA245014 and 2019GXNSFBA245055)the National Natural Science Foundation of China(Nos.51661009 and 51901054)the Science and Technology Base and Talent Special Project of Guangxi Province(Nos.AD19245162 and AD19245030)。
文摘As a promising anode for sodium-ion batteries(SIBs),the performance of SnO_(2) is still limited by inferior electronic conductivity and large volume change.To address this issue,herein,the intergrowth structured SnO_(2)/CoSn_(2)@C nanocomposite has been fabricated by a two-step process combining hydrothermal synthesis with carbon coating.
基金the National Natural Science Foundation of China(No.51261003)the Natural Foundation of Guangxi Province(Nos.2012GXNS FGA060002 and 2011GXNSFD018004)。
文摘La_(1-x)Mg_(x)Ni_(2.8)Co_(0.4)Mn_(0.1)Al_(0.2)(x=0.25,0.30,0.33)alloys were prepared by induction melting followed by annealing treatments(1,073 K)for 10 h.The structure and electrochemical properties of La_(1-x)Mg_(x)Ni_(2.8)Co_(0.4)Mn_(0.1)Al_(0.2)(x=0.25,0.30,0.33)hydrogen storage alloys were investigated by X-ray powder diffraction(XRD)and electrochemical measurement methods.XRD results reveal that all the alloys mainly consist of LaNi5 phase and La2 Ni7 phase.The electrochemical experiments demonstrate that the substitution of Mg for La can increase the maximum discharge capacity and improve the high-rate dischargeability of the alloy electrodes.The high-rate dischargeability of alloy electrodes increases from 39.4%to63.1%with x increasing from 0.25 to 0.33 at discharge current density of 1,500 mA·g^(-1).However,the addition of Mg reduces the cycling stability of the electrodes.Furthermore,the results obtained from the electrochemical impedance spectroscopy and linear polarization measurements show that the hydriding kinetics on the hydrogen storage alloys are controlled by charge-transfer step.
