1.IntroductionDunn and Farrington[1]found that theNa ion in Naβ″-alumina single crystal canbe exchanged completely or partially withGd;,Nd;,Eu;,Yb;,Sm;,Tb;,Dy;,Bi;and Pr;ions,but no reports havebeen published about ...1.IntroductionDunn and Farrington[1]found that theNa ion in Naβ″-alumina single crystal canbe exchanged completely or partially withGd;,Nd;,Eu;,Yb;,Sm;,Tb;,Dy;,Bi;and Pr;ions,but no reports havebeen published about the ion exchange reac-tion between La3+ and Naβ″-alumina.If anion exchanged polycrystalline β″-alumina isavailable and its ionic conductivity is highenough to be applied as a solid electrolyte inthe galvanic cell,it can be used in various展开更多
This paper reports the kinetic process of Ag ion exchange for the polycrystalline Na-β'-Al2O3.The interdiffusion coefficients in the process of Ag+ and Na+ ion exchange have been calculated with an 'one dimen...This paper reports the kinetic process of Ag ion exchange for the polycrystalline Na-β'-Al2O3.The interdiffusion coefficients in the process of Ag+ and Na+ ion exchange have been calculated with an 'one dimensional double side diffusion model'. Microstructures of the samples were observed and analysed by XRD, EMPA, SEM. The results of the conductivity measurements for samples with Na+, Ag+ and Na+-Ag+ mobile ions are presented and explained展开更多
The propensity of metallic Na dendrites from uneven electrodeposits and the low Coulombic efficiency due to the inevitable existence of "dead sodium" are crucial barriers to realizing the Na metal anode.Here...The propensity of metallic Na dendrites from uneven electrodeposits and the low Coulombic efficiency due to the inevitable existence of "dead sodium" are crucial barriers to realizing the Na metal anode.Herein,we report a multifunctional sodiophilic skeleton based on the packing of hard carbon(HC)microspheres for stable sodium metal electrodeposition without "dead sodium".Firstly,HC is sodiophilic substrate due to the intrinsic heteroatoms or defects which is a favor for the nucleation of Na.Secondly,silver nanoparticles electroplating on HC(Ag-HC)was adopted to boost the Na diffusion and further regulate the uniform Na metal epitaxial deposition due to well compatibility with AIMD simulation.Finally,the packing of HC microspheres provides the inner space for Na plating.Importantly,it was first found by Cryo-TEM that Na metal deposition in nanoscale is achieved by oriented attachment along[110]direction,leading to the formation of polycrystalline Na metal film on Ag-HC.Such epitaxial deposition can efficiently reduce the formation of "dead sodium" as revealed by chromatography tests,allowing the high Coulombic efficiency and good cycling stability robust kinetics.Finally,HC-Ag||Na_(3)V_(2)(PO_(4))_(3)full cell with a low negative/positive ratio of 0.6 is firstly achieved and displays good cycling stability.This finding provides a new practical strategy without pre-plating of Na metals and demonstrates a highly reversible polycrystalline Na metal anode toward a high-energy Na-based battery.展开更多
文摘1.IntroductionDunn and Farrington[1]found that theNa ion in Naβ″-alumina single crystal canbe exchanged completely or partially withGd;,Nd;,Eu;,Yb;,Sm;,Tb;,Dy;,Bi;and Pr;ions,but no reports havebeen published about the ion exchange reac-tion between La3+ and Naβ″-alumina.If anion exchanged polycrystalline β″-alumina isavailable and its ionic conductivity is highenough to be applied as a solid electrolyte inthe galvanic cell,it can be used in various
文摘This paper reports the kinetic process of Ag ion exchange for the polycrystalline Na-β'-Al2O3.The interdiffusion coefficients in the process of Ag+ and Na+ ion exchange have been calculated with an 'one dimensional double side diffusion model'. Microstructures of the samples were observed and analysed by XRD, EMPA, SEM. The results of the conductivity measurements for samples with Na+, Ag+ and Na+-Ag+ mobile ions are presented and explained
基金financially supported by the National Natural Science Foundation of China(NSFC 51874099)the National Science Foundation of Fujian Province’s Key Project(2021J02031)。
文摘The propensity of metallic Na dendrites from uneven electrodeposits and the low Coulombic efficiency due to the inevitable existence of "dead sodium" are crucial barriers to realizing the Na metal anode.Herein,we report a multifunctional sodiophilic skeleton based on the packing of hard carbon(HC)microspheres for stable sodium metal electrodeposition without "dead sodium".Firstly,HC is sodiophilic substrate due to the intrinsic heteroatoms or defects which is a favor for the nucleation of Na.Secondly,silver nanoparticles electroplating on HC(Ag-HC)was adopted to boost the Na diffusion and further regulate the uniform Na metal epitaxial deposition due to well compatibility with AIMD simulation.Finally,the packing of HC microspheres provides the inner space for Na plating.Importantly,it was first found by Cryo-TEM that Na metal deposition in nanoscale is achieved by oriented attachment along[110]direction,leading to the formation of polycrystalline Na metal film on Ag-HC.Such epitaxial deposition can efficiently reduce the formation of "dead sodium" as revealed by chromatography tests,allowing the high Coulombic efficiency and good cycling stability robust kinetics.Finally,HC-Ag||Na_(3)V_(2)(PO_(4))_(3)full cell with a low negative/positive ratio of 0.6 is firstly achieved and displays good cycling stability.This finding provides a new practical strategy without pre-plating of Na metals and demonstrates a highly reversible polycrystalline Na metal anode toward a high-energy Na-based battery.
